tag:blogger.com,1999:blog-85287150020400675672024-03-14T05:26:43.874+01:00Costruzioni marittimeRadiuk Raikohttp://www.blogger.com/profile/16969685561223667013noreply@blogger.comBlogger37125tag:blogger.com,1999:blog-8528715002040067567.post-22904827370579165352015-01-11T02:19:00.000+01:002015-01-11T02:19:31.170+01:00Indice<ul>
<li><b><a href="http://costruzionimarittime.blogspot.it/2013/07/generazione-delle-onde.html">Generazione delle onde</a></b></li>
<li><b><a href="http://costruzionimarittime.blogspot.it/2013/07/stato-di-mare-e-mareggiata.html">Stato di mare e mareggiata</a></b></li>
<li><b><a href="http://costruzionimarittime.blogspot.it/2013/07/onde-regolari-progressive.html">Onde regolari progressive</a></b></li>
<li><b><a href="http://costruzionimarittime.blogspot.it/2013/07/cinematica-del-moto.html">Cinematica del moto</a></b></li>
<li><b><a href="http://costruzionimarittime.blogspot.it/2013/07/pressione.html">Pressione</a></b></li>
<li><b><a href="http://costruzionimarittime.blogspot.it/2013/07/densita-e-flusso-di-energia.html">Densità e flusso di energia</a></b></li>
<li><b><a href="http://costruzionimarittime.blogspot.it/2013/07/effetti-di-non-linearita.html">Effetti di non linearità</a></b></li>
<li><b><a href="http://costruzionimarittime.blogspot.it/2013/07/frangimento-delle-onde-regolari.html">Frangimento delle onde regolari</a></b></li>
<li><b><a href="http://costruzionimarittime.blogspot.it/2013/08/onde-stazionarie-al-primo-ordine-di.html">Onde stazionarie al primo ordine di approssimazion...</a></b></li>
<li><b><a href="http://costruzionimarittime.blogspot.it/2013/08/onde-stazionarie-al-secondo-ordine-di.html">Onde stazionarie al secondo ordine di approssimazi...</a></b></li>
<li><b><a href="http://costruzionimarittime.blogspot.it/2013/08/propagazione-bidimensionale-delle-onde.html">Propagazione bidimensionale delle onde: shoaling</a></b></li>
<li><a href="http://costruzionimarittime.blogspot.it/2013/08/attacco-frontale.html"><b>Attacco frontale</b></a></li>
<li><a href="http://costruzionimarittime.blogspot.it/2013/08/attacco-non-frontale-rifrazione.html"><b>Attacco non frontale: Rifrazione</b></a></li>
<li><a href="http://costruzionimarittime.blogspot.it/2013/08/moti-tridimensionali.html"><b>Moti tridimensionali</b></a></li>
<li><a href="http://costruzionimarittime.blogspot.it/2013/08/variazione-del-livello-medio-rispetto.html"><b>Variazione del livello medio rispetto al livello d...</b></a></li>
<li><a href="http://costruzionimarittime.blogspot.it/2013/08/onde-irregolari-stato-di-mare-su.html"><b>Onde irregolari: Stato di mare su profondità infin...</b></a></li>
<li><a href="http://costruzionimarittime.blogspot.it/2013/08/descrizione-spettrale-degli-stati-di.html"><b>Descrizione spettrale degli stati di mare su profo...</b></a></li>
<li><a href="http://costruzionimarittime.blogspot.it/2013/08/descrizione-statistica-delle-onde.html"><b>Descrizione statistica delle onde irregolari</b></a></li>
<li><a href="http://costruzionimarittime.blogspot.it/2013/08/modelli-di-previsioni.html"><b>Modelli di previsioni</b></a></li>
<li><a href="http://costruzionimarittime.blogspot.it/2013/08/bilancio-energetico-dellarea-di.html"><b>Bilancio energetico dell'area di generazione</b></a></li>
<li><a href="http://costruzionimarittime.blogspot.it/2013/08/modello-rls.html"><b>Modello RLS</b></a></li>
<li><a href="http://costruzionimarittime.blogspot.it/2013/08/metodi-di-previsione-lungo-termine.html"><b>Metodi di previsione a lungo termine</b></a></li>
<li><b><a href="http://costruzionimarittime.blogspot.it/2013/08/trasferimento-del-clima-ondoso-verso-le.html">Trasferimento del clima ondoso verso le basse prof...</a></b></li>
<li><b><br /></b></li>
<li><b><a href="http://costruzionimarittime.blogspot.it/2013/08/processi-costieri-definizione-di.html">PROCESSI COSTIERI: Definizione di litorale e della...</a></b></li>
<li><b><a href="http://costruzionimarittime.blogspot.it/2013/08/trasporto-litoraneo.html">Trasporto litoraneo</a></b></li>
<li><b><a href="http://costruzionimarittime.blogspot.it/2013/08/profilo-medio-di-equilibrio-profondita.html">Profilo medio di equilibrio, profondità di chiusur...</a></b></li>
<li><b><a href="http://costruzionimarittime.blogspot.it/2013/08/trasporto-solido-longitudinale.html">Trasporto solido longitudinale</a></b></li>
<li><b><br /></b></li>
<li><b><a href="http://costruzionimarittime.blogspot.it/2013/08/strutture-di-protezione-del-litorale.html">STRUTTURE DI PROTEZIONE DEL LITORALE</a></b></li>
<li><b><a href="http://costruzionimarittime.blogspot.it/2013/08/tipologie-di-struttura.html">Tipologie di struttura</a></b></li>
<li><a href="http://costruzionimarittime.blogspot.it/2013/08/strutture-parete-verticale.html"><b>Strutture a parete verticale</b></a></li>
<li><a href="http://costruzionimarittime.blogspot.it/2013/08/diga-gettata.html"><b>Diga a gettata</b></a></li>
<li><a href="http://costruzionimarittime.blogspot.it/2013/08/dimensionamento-della-della-mantellata.html"><b>Dimensionamento della mantellata esterna</b></a></li>
<li><a href="http://costruzionimarittime.blogspot.it/2013/08/onde-regolari.html"><b>Onde regolari</b></a></li>
<li><a href="http://costruzionimarittime.blogspot.it/2013/08/verifica-della-risposta-idraulica.html"><b>Verifica della risposta idraulica</b></a></li>
<li><a href="http://costruzionimarittime.blogspot.it/2013/08/dimensionamento-delle-strutture-cresta.html"><b>Dimensionamento delle strutture a cresta bassa o s...</b></a></li>
</ul>
Anonymoushttp://www.blogger.com/profile/12757376466571315711noreply@blogger.com0tag:blogger.com,1999:blog-8528715002040067567.post-32422281671595768072014-10-08T15:59:00.000+02:002015-10-22T16:05:53.504+02:00Costruzioni marittime<div dir="ltr" style="text-align: left;" trbidi="on">
<b><a href="http://costruzionimarittime.blogspot.com/" target="_blank">Costruzione marittime</a></b><br />
<br />
<select onchange="self.location.href=this.value;">
<optgroup label="Indice 1">
<option value="
http://costruzionimarittime.blogspot.it/2013/07/generazione-delle-onde.html
">
Generazione delle onde
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/07/stato-di-mare-e-mareggiata.html
">
Stato di mare e mareggiata
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/07/onde-regolari-progressive.html
">
Onde regolari progressive
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/07/cinematica-del-moto.html
">
Cinematica del moto
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/07/pressione.html
">
Pressione
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/07/densita-e-flusso-di-energia.html
">
Densità e flusso di energia
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/07/effetti-di-non-linearita.html
">
Effetti di non linearità
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/07/frangimento-delle-onde-regolari.html
">
Frangimento delle onde regolari
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/08/onde-stazionarie-al-primo-ordine-di.html
">
Onde stazionarie al primo ordine di approssimazione
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/08/onde-stazionarie-al-secondo-ordine-di.html
">
Onde stazionarie al secondo ordine di approssimazione
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/08/propagazione-bidimensionale-delle-onde.html
">
Propagazione bidimensionale delle onde: shoaling
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/08/attacco-frontale.html
">
Attacco frontale
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/08/attacco-non-frontale-rifrazione.html
">
Attacco non frontale: Rifrazione
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/08/moti-tridimensionali.html
">
Moti tridimensionali
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/08/variazione-del-livello-medio-rispetto.html
">
Variazione del livello medio rispetto al livello di quiete
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/08/onde-irregolari-stato-di-mare-su.html
">
Onde irregolari: Stato di mare su profondità infinita
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/08/descrizione-spettrale-degli-stati-di.html
">
Descrizione spettrale degli stati di mare su profondità infinita
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/08/descrizione-statistica-delle-onde.html
">
Descrizione statistica delle onde irregolari
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/08/modelli-di-previsioni.html
">
Modelli di previsioni
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/08/bilancio-energetico-dellarea-di.html
">
Bilancio energetico dell'area di generazione
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/08/modello-rls.html
">
Modello RLS
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/08/metodi-di-previsione-lungo-termine.html
">
Metodi di previsione a lungo termine
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/08/trasferimento-del-clima-ondoso-verso-le.html
">
Trasferimento del clima ondoso verso le basse profondità
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/08/processi-costieri-definizione-di.html
">
PROCESSI COSTIERI: Definizione di litorale e della sua dinamica
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/08/trasporto-litoraneo.html
">
Trasporto litoraneo
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/08/profilo-medio-di-equilibrio-profondita.html
">
Profilo medio di equilibrio, profondità di chiusura
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/08/trasporto-solido-longitudinale.html
">
Trasporto solido longitudinale
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/08/strutture-di-protezione-del-litorale.html
">
STRUTTURE DI PROTEZIONE DEL LITORALE
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/08/tipologie-di-struttura.html
">
Tipologie di struttura
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/08/strutture-parete-verticale.html
">
Strutture a parete verticale
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/08/diga-gettata.html
">
Diga a gettata
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/08/dimensionamento-della-della-mantellata.html
">
Dimensionamento della mantellata esterna
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/08/onde-regolari.html
">
Onde regolari
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/08/verifica-della-risposta-idraulica.html
">
Verifica della risposta idraulica
</option>
<option value="
http://costruzionimarittime.blogspot.it/2013/08/dimensionamento-delle-strutture-cresta.html
">
Dimensionamento delle strutture a cresta bassa o sommerse
</option>
</optgroup></select></div>
Anonymoushttp://www.blogger.com/profile/12757376466571315711noreply@blogger.com0tag:blogger.com,1999:blog-8528715002040067567.post-82824605583966226562013-08-06T01:32:00.001+02:002013-08-06T01:32:39.917+02:00Dimensionamento delle strutture a cresta bassa o sommerse<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;">Le
strutture a cresta bassa presentano una struttura del tutto analoga
alle dighe a gettata, tuttavia sono realizzate per consentire la
tracimazione, in quanto non rispettano l’altezza necessaria a
limitare l’overtopping dell’onda di progetto, infatti sono
sommerse o a meno di 1,5 metri.</span><br />
<div style="font-weight: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Consentendo
la tracimazione del moto ondoso occorre dimensionare anche la
mantellata interna come quella esterna. La funzione principale di
tali dighe è quella di attenuare il moto ondoso, e non di arrestarlo
completamente: la dimensione dei massi non sarà quindi dimensionata
al pari di dighe non tracimabili. </span></span></span>
</div>
<div style="font-weight: normal; margin-bottom: 0cm;">
<br /></div>
<div align="CENTER" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><u><b>Dimensionamento</b></u></i></span></span></span></div>
<div style="font-style: normal; font-weight: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Consideriamo
la trattazione di Van der Meer nell'ipotesi di essere in condizioni
di frangimento plunging:</span></span></span></div>
<div style="font-style: normal; font-weight: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><br /></span></span></span></div>
<div style="font-style: normal; font-weight: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><br /></span></span></span></div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=N_s&space;=&space;\frac{H}{\nabla&space;\cdot&space;d_{50}}=(k_d&space;\cdot&space;cot&space;\alpha)^{\frac{1}{3}}" target="_blank"><img src="http://latex.codecogs.com/png.latex?N_s&space;=&space;\frac{H}{\nabla&space;\cdot&space;d_{50}}=(k_d&space;\cdot&space;cot&space;\alpha)^{\frac{1}{3}}" title="N_s = \frac{H}{\nabla \cdot d_{50}}=(k_d \cdot cot \alpha)^{\frac{1}{3}}" /></a><br />
<br /></div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=\xi_{0m}=\frac{tan&space;\alpha}{\sqrt{\frac{H_s}{g&space;\cdot&space;T_{0m}^2}}}" target="_blank"><img src="http://latex.codecogs.com/png.latex?\xi_{0m}=\frac{tan&space;\alpha}{\sqrt{\frac{H_s}{g&space;\cdot&space;T_{0m}^2}}}" title="\xi_{0m}=\frac{tan \alpha}{\sqrt{\frac{H_s}{g \cdot T_{0m}^2}}}" /></a></div>
<div style="text-align: center;">
<br /></div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=T_{0m}=0,8&space;T_p" target="_blank"><img src="http://latex.codecogs.com/png.latex?T_{0m}=0,8&space;T_p" title="T_{0m}=0,8 T_p" /></a>
<br />
<br /></div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=\frac{H_s}{\nabla&space;\cdot&space;d_{50}}=6,2&space;\cdot&space;P^{0,18}&space;\cdot&space;\left(&space;\frac{S}{\sqrt{N}}&space;\right&space;)^{0,2}&space;\cdot&space;\xi^{-0,5}_{0m}" target="_blank"><img src="http://latex.codecogs.com/png.latex?\frac{H_s}{\nabla&space;\cdot&space;d_{50}}=6,2&space;\cdot&space;P^{0,18}&space;\cdot&space;\left(&space;\frac{S}{\sqrt{N}}&space;\right&space;)^{0,2}&space;\cdot&space;\xi^{-0,5}_{0m}" title="\frac{H_s}{\nabla \cdot d_{50}}=6,2 \cdot P^{0,18} \cdot \left( \frac{S}{\sqrt{N}} \right )^{0,2} \cdot \xi^{-0,5}_{0m}" /></a>
</div>
<div style="text-align: center;">
<br /></div>
<div style="text-align: center;">
</div>
<div style="font-weight: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Possiamo
quindi calcolare la dimensione media dei massi naturali per una dig</span></span></span><span class="Apple-style-span" style="font-family: 'Times New Roman', serif;">a
non tracimabile, inserendo un coefficiente riduttivo.</span></div>
<div style="font-weight: normal; margin-bottom: 0cm;">
<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;"><br /></span></div>
<div style="font-weight: normal; margin-bottom: 0cm;">
<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;"><br /></span></div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=R_{Dn50}=\frac{1}{1,25&space;-&space;4,8&space;R_p^{*}}" target="_blank"><img src="http://latex.codecogs.com/png.latex?R_{Dn50}=\frac{1}{1,25&space;-&space;4,8&space;R_p^{*}}" title="R_{Dn50}=\frac{1}{1,25 - 4,8 R_p^{*}}" /></a>
</div>
<div style="text-align: center;">
<br /></div>
<div style="text-align: left;">
Dove:</div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=R_{p}^{*}=\left(&space;\frac{R_c}{H_s}&space;\right&space;)&space;\cdot&space;\left(&space;\frac{S_{0p}}{2\pi}\right)^{0,5}" target="_blank"><img src="http://latex.codecogs.com/png.latex?R_{p}^{*}=\left(&space;\frac{R_c}{H_s}&space;\right&space;)&space;\cdot&space;\left(&space;\frac{S_{0p}}{2\pi}\right)^{0,5}" title="R_{p}^{*}=\left( \frac{R_c}{H_s} \right ) \cdot \left( \frac{S_{0p}}{2\pi}\right)^{0,5}" /></a>
<br />
<br /></div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=S_{0p}=\frac{H_s}{L_{0p}}" target="_blank"><img src="http://latex.codecogs.com/png.latex?S_{0p}=\frac{H_s}{L_{0p}}" title="S_{0p}=\frac{H_s}{L_{0p}}" /></a>
</div>
<div style="text-align: center;">
<br /></div>
<div style="text-align: center;">
</div>
<div align="LEFT" style="font-weight: normal; margin-bottom: 0cm;">
<span style="font-family: Times New Roman, serif;"><span style="color: black;"><span style="font-size: small;">Il
diametro dei massi che dovranno essere posizionati, sarà:</span></span></span></div>
<div align="LEFT" style="font-weight: normal; margin-bottom: 0cm;">
<span style="font-family: Times New Roman, serif;"><span style="color: black;"><span style="font-size: small;"> </span></span></span>
</div>
<a href="http://www.codecogs.com/eqnedit.php?latex=D_{50eff}=&space;D_{50}&space;\cdot&space;R_{Dn50}" target="_blank"><img src="http://latex.codecogs.com/png.latex?D_{50eff}=&space;D_{50}&space;\cdot&space;R_{Dn50}" title="D_{50eff}= D_{50} \cdot R_{Dn50}" /></a>
Radiuk Raikohttp://www.blogger.com/profile/16969685561223667013noreply@blogger.com0tag:blogger.com,1999:blog-8528715002040067567.post-88434388858255339532013-08-06T01:14:00.001+02:002013-08-06T01:14:40.621+02:00Verifica della risposta idraulica<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;">L'altezza
totale della struttura dipende dalla risposta idraulica di questa,
che dipenderà da tre fattori:</span><br />
<ul>
<li><div align="LEFT" style="font-weight: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>run-up</i></span></span></span></div>
</li>
<li><div align="LEFT" style="font-weight: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>run-down</i></span></span></span></div>
</li>
<li><div align="LEFT" style="font-weight: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>overtopping</i></span></span></span></div>
</li>
</ul>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Il
run-up fa riferimento ad un valore che viene superato solo dal 2%
delle onde che costituiscono lo stato di mare che viene usato per la
progettazione:</span></span></span></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><br /></span></span></span></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><br /></span></span></span></div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=\frac&space;{R_{u2\%}}{H_s}&space;=&space;1,5&space;\gamma&space;\cdot&space;\xi_p" target="_blank"><img src="http://latex.codecogs.com/png.latex?\frac&space;{R_{u2\%}}{H_s}&space;=&space;1,5&space;\gamma&space;\cdot&space;\xi_p" title="\frac {R_{u2\%}}{H_s} = 1,5 \gamma \cdot \xi_p" /></a></div>
<div style="text-align: center;">
<br /></div>
<div style="text-align: center;">
</div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Dove:</span></span></span></div>
<ul>
<li><div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">γ
= 0,5</span></span></span></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">ξ</span></span></span></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">p</span></span></span></span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">
= 2</span></span></span></span></span></span></div>
</li>
</ul>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Sostituendo:</span></span></span></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><br /></span></span></span></div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=R_{u2\%}=1,5&space;H_s" target="_blank"><img src="http://latex.codecogs.com/png.latex?R_{u2\%}=1,5&space;H_s" title="R_{u2\%}=1,5 H_s" /></a>
</div>
<br />
<br />
<div align="LEFT" style="margin-bottom: 0cm;">
Per il run down si fa
riferimento ad una formula che tiene conto del valore che viene
superato solo dal 2% delle onde che costituiscono lo stato di mare di
progetto:</div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=\frac{R_{d2\%}}{H_s}=2,1&space;\cdot&space;(tan&space;\alpha)^{0,5}&space;-&space;1,2&space;P^{0,15}\approx&space;1" target="_blank"><img src="http://latex.codecogs.com/png.latex?\frac{R_{d2\%}}{H_s}=2,1&space;\cdot&space;(tan&space;\alpha)^{0,5}&space;-&space;1,2&space;P^{0,15}\approx&space;1" title="\frac{R_{d2\%}}{H_s}=2,1 \cdot (tan \alpha)^{0,5} - 1,2 P^{0,15}\approx 1" /></a>
</div>
<div style="text-align: center;">
<br /></div>
<div style="text-align: center;">
</div>
<div align="LEFT" style="font-style: normal; margin-bottom: 0cm;">
Calcolando
l'overtopping convenzionale possiamo sapere quant'è la portata
d'acqua che mediamente tracima e quindi esprime il grado di
fruibilità che si può concedere alla struttura:</div>
<div align="LEFT" style="font-style: normal; margin-bottom: 0cm;">
<br /></div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=\frac{q}{\frac{L_m^2}{T_m}}=3,2&space;\cdot&space;10^{-5}&space;\cdot&space;\left(&space;\frac{H_s}{R_c}&space;\right&space;)^3&space;\cdot&space;\frac{H_s^2}{A_{cb}}&space;\cdot&space;tan&space;(\alpha)" target="_blank"><img src="http://latex.codecogs.com/png.latex?\frac{q}{\frac{L_m^2}{T_m}}=3,2&space;\cdot&space;10^{-5}&space;\cdot&space;\left(&space;\frac{H_s}{R_c}&space;\right&space;)^3&space;\cdot&space;\frac{H_s^2}{A_{cb}}&space;\cdot&space;tan&space;(\alpha)" title="\frac{q}{\frac{L_m^2}{T_m}}=3,2 \cdot 10^{-5} \cdot \left( \frac{H_s}{R_c} \right )^3 \cdot \frac{H_s^2}{A_{cb}} \cdot tan (\alpha)" /></a>
</div>
<div style="text-align: center;">
<br /></div>
<div style="text-align: center;">
</div>
<div align="LEFT" style="font-style: normal; margin-bottom: 0cm;">
Dove:</div>
<ul>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<i>H</i><sub><i>s</i></sub><span style="font-style: normal;">
: onda di progetto:</span></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<i>R</i><sub><i>c</i></sub><span style="font-style: normal;">
: quota della cresta dell'opera rispetto allo SWL</span></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<i>B</i><span style="font-style: normal;">
: estensione della berma</span></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<i>A</i><sub><i>c</i></sub><sub><span style="font-style: normal;">
</span></sub><span style="font-style: normal;">: </span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="font-weight: normal;">quota
della berma</span></span></span></span></span></div>
</li>
</ul>
Radiuk Raikohttp://www.blogger.com/profile/16969685561223667013noreply@blogger.com0tag:blogger.com,1999:blog-8528715002040067567.post-4845155308369691192013-08-04T23:26:00.002+02:002013-08-04T23:26:43.672+02:00Onde regolari<br />
<div align="LEFT" style="line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="font-family: Times New Roman, serif;"><b>Onde regolari</b></span></div>
</div>
<ol>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><a href="http://costruzionimarittime.blogspot.it/2013/07/generazione-delle-onde.html">Generazione delle onde</a></span></span></span></div>
</div>
</li>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><a href="http://costruzionimarittime.blogspot.it/2013/07/stato-di-mare-e-mareggiata.html">Stato di mare e mareggiata</a></span></span></span></div>
</div>
</li>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><a href="http://costruzionimarittime.blogspot.it/2013/07/onde-regolari-progressive.html">Onde regolari progressive</a></span></span></span></div>
</div>
</li>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><a href="http://costruzionimarittime.blogspot.it/2013/07/cinematica-del-moto.html">Cinematica del moto</a></span></span></span></div>
</div>
</li>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><a href="http://costruzionimarittime.blogspot.it/2013/07/pressione.html">Pressione</a></span></span></span></div>
</div>
</li>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><a href="http://costruzionimarittime.blogspot.it/2013/07/densita-e-flusso-di-energia.html">Densità e flusso di energia</a></span></span></span></div>
</div>
</li>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><a href="http://costruzionimarittime.blogspot.it/2013/07/effetti-di-non-linearita.html">Effetti di non linearità</a></span></span></span></div>
</div>
</li>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><a href="http://costruzionimarittime.blogspot.it/2013/07/frangimento-delle-onde-regolari.html">Frangimento delle onde regolari</a></span></span></span></div>
</div>
</li>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><a href="http://costruzionimarittime.blogspot.it/2013/08/onde-stazionarie-al-primo-ordine-di.html">Onde stazionarie al primo ordine di approssimazione</a></span></span></span></div>
</div>
</li>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><a href="http://costruzionimarittime.blogspot.it/2013/08/onde-stazionarie-al-secondo-ordine-di.html">Onde stazionarie al secondo ordine di approssimazione</a></span></div>
</div>
</li>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><a href="http://costruzionimarittime.blogspot.it/2013/08/propagazione-bidimensionale-delle-onde.html">Propagazione bidimensionale delle onde regolari</a></span></div>
</div>
<ol>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><a href="http://costruzionimarittime.blogspot.it/2013/08/attacco-frontale.html">Attacco frontale</a></span></span></span></div>
</div>
<ol>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><a href="http://costruzionimarittime.blogspot.it/2013/08/attacco-frontale.html">Riflessione</a></span></span></span></div>
</div>
</li>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><a href="http://costruzionimarittime.blogspot.it/2013/08/attacco-frontale.html">Effetti dissipativi al fondo</a></span></span></span></div>
</div>
</li>
</ol>
</li>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><a href="http://costruzionimarittime.blogspot.it/2013/08/attacco-non-frontale-rifrazione.html">Attacco non frontale</a></span></span></span></div>
</div>
<ol>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><a href="http://costruzionimarittime.blogspot.it/2013/08/attacco-non-frontale-rifrazione.html">Rifrazione</a></span></span></span></div>
</div>
</li>
</ol>
</li>
</ol>
</li>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><a href="http://costruzionimarittime.blogspot.it/2013/08/moti-tridimensionali.html">Moti tridimensionali</a></span></div>
</div>
<ol>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><a href="http://costruzionimarittime.blogspot.it/2013/08/moti-tridimensionali.html">Difrazione</a></span></span></span></div>
</div>
</li>
</ol>
</li>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><a href="http://costruzionimarittime.blogspot.it/2013/08/variazione-del-livello-medio-rispetto.html">Variazione del livello medio rispetto al livello di quiete</a></span></span></span></div>
</div>
</li>
</ol>
Radiuk Raikohttp://www.blogger.com/profile/16969685561223667013noreply@blogger.com0tag:blogger.com,1999:blog-8528715002040067567.post-67820811549196406262013-08-02T21:30:00.000+02:002013-08-05T00:42:57.077+02:00Dimensionamento della mantellata esterna <span class="Apple-style-span" style="font-family: WalkwaySemiBold;"><span style="font-family: Times New Roman, serif;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">Si
devono determinare gli elementi che si utilizzano e la relativa massa
</span></span></span></span></span><span class="Apple-style-span" style="font-family: WalkwaySemiBold;"><i><span style="font-family: Times New Roman, serif;"><span style="text-decoration: none;"><span style="font-weight: normal;">M,
</span></span></span></i></span><span class="Apple-style-span" style="font-family: WalkwaySemiBold;"><span style="font-family: Times New Roman, serif;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">da
poter calcolare e verificare che la mantellata rimanga stabile sotto
l'azione dell'onda di progetto. Si può utilizzare la formula di
</span></span></span></span></span><span class="Apple-style-span" style="font-family: WalkwaySemiBold;"><i><span style="font-family: Times New Roman, serif;"><span style="text-decoration: none;"><span style="font-weight: normal;">Hudson</span></span></span></i></span><span class="Apple-style-span" style="font-family: WalkwaySemiBold;"><span style="font-family: Times New Roman, serif;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">
per onde regolari:</span></span></span></span></span><br />
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=M=\rho_s&space;H^3&space;\frac{tanh&space;(\alpha)}{\left(\frac{\rho_s-\rho_w}{\rho_w}&space;\right&space;)&space;^3&space;\cdot&space;k_d}" target="_blank"><img src="http://latex.codecogs.com/gif.latex?M=\rho_s&space;H^3&space;\frac{tanh&space;(\alpha)}{\left(\frac{\rho_s-\rho_w}{\rho_w}&space;\right&space;)&space;^3&space;\cdot&space;k_d}" title="M=\rho_s H^3 \frac{tanh (\alpha)}{\left(\frac{\rho_s-\rho_w}{\rho_w} \right ) ^3 \cdot k_d}" /></a></div>
<div style="text-align: center;">
<br /></div>
<div style="text-align: center;">
</div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Dove:</span></span></span></div>
<ul>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">α
: </span></span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">inclinazione
della mantellata rispetto all’orizzontale;</span></span></span></span></span></span></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">k</span></span></span></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">d
</span></span></span></span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">:
coefficiente di stabilità di derivazione sperimentale </span></span></span></span></span></span>
</div>
</li>
<li><div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">H
: altezza d'onda di progetto</span></span></span></div>
</li>
<li><div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">M
: massa dei massi</span></span></span></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">ρ</span></span></span></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">s</span></span></span></span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">
: densità del materiale di progetto</span></span></span></span></span></span></div>
</li>
</ul>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<br /></div>
<div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">La
formula di Hudson non tiene conto che la diga può subire dei
danneggiamenti, per questo è stato introdotto un coefficiente </span></span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">D%
</span></span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">che
rappresenta la percentuale dei massi spostati rispetto a tutti i
massi della zona critica compresa tra la cresta dell'onda e la
profondità pari ad </span></span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">H.</span></span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">
La mantellata è ritenuta stabile fino a quando </span></span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">D%
< 5% </span></span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">rispetto
alle condizioni di progetto.</span></span></span></span></span></span></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<br /></div>
<div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">La
formula di Hudson può essere espressa attraverso l'uso del numero di
stabilità N</span></span></span></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">s</span></span></span></span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">:</span></span></span></span></span></span></div>
<div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;"><br /></span></span></span></span></span></span></div>
<div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;"><br /></span></span></span></span></span></span></div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=N_s=\frac{H}{\nabla&space;\cdot&space;D}=(k_d&space;\cdot&space;cot&space;\alpha)^{\frac{1}{3}}" target="_blank"><img src="http://latex.codecogs.com/png.latex?N_s=\frac{H}{\nabla&space;\cdot&space;D}=(k_d&space;\cdot&space;cot&space;\alpha)^{\frac{1}{3}}" title="N_s=\frac{H}{\nabla \cdot D}=(k_d \cdot cot \alpha)^{\frac{1}{3}}" /></a> </div>
<div style="text-align: center;">
<br /></div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=D_{50}=\left(&space;\frac{M_{50}}{\rho_s}&space;\right&space;)^{\frac{1}{3}}" target="_blank"><img src="http://latex.codecogs.com/png.latex?D_{50}=\left(&space;\frac{M_{50}}{\rho_s}&space;\right&space;)^{\frac{1}{3}}" title="D_{50}=\left( \frac{M_{50}}{\rho_s} \right )^{\frac{1}{3}}" /></a><br />
<br />
<br />
<div align="LEFT" style="font-weight: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Van
der Meer introdusse una nuova formulazione basata su esperimenti con
onde irregolari che teneva conto dei seguenti fattori:</span></span></span></div>
<ul>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">H</span></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">s</span></span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">
: </span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="font-weight: normal;">altezza
d'onda significativa;</span></span></span></span></span></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">P
: </span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="font-weight: normal;">permeabilità
nozionale della mantellata, varia tra 0,1 a 0,6 dipendentemente dal
sottostrato, se è impermeabile o totalmente permeabile;</span></span></span></span></span></div>
</li>
<li style="text-align: left;"><i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">T</span></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">m </span></span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">= <span class="Apple-style-span" style="font-family: Times; font-style: normal;"><i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">T</span></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">0m </span></span></span></sub></span></i></span> =0,8 T</span></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">p</span></span></span></sub></span></i><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="font-weight: normal;">
</span></span></span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="font-weight: normal;">:
Periodo medio</span></span></span></span></span></li>
<li style="text-align: left;"><i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">N</span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="font-weight: normal;">
numero di onde considerate;</span></span></span></span></span></li>
<li style="text-align: left;"><i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">S
</span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="font-weight: normal;">grado
di danneggiamento = </span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="font-weight: normal;">A</span></span></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="font-weight: normal;">e</span></span></span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="font-weight: normal;">/D</span></span></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="font-weight: normal;">50</span></span></span></span></sub></span><span style="color: black;"><sup><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="font-weight: normal;">2</span></span></span></span></sup></span></li>
<li style="text-align: left;"><span style="color: black;"><sup><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">
<ul>
<li style="font-style: normal;"><i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">A</span></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">e</span></span></span></sub></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="font-weight: normal;">
è la superficie danneggiata;</span></span></span></span></span></li>
<li><i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">D</span></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">50</span></span></span></sub></span></i><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="font-weight: normal;">
</span></span></span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="font-weight: normal;">il
diametro medio dei massi usati;</span></span></span></span></span></li>
</ul>
</span></span></span></sup></span></li>
</ul>
<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;">Numero
di Irribarren secondo Van der Meer:</span><br />
<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;"><br /></span></div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=\xi&space;=\frac{tan&space;\alpha}{\sqrt{\frac{H_s}{g&space;\cdot&space;T_{om}^2}}}" target="_blank"><img src="http://latex.codecogs.com/gif.latex?\xi&space;=\frac{tan&space;\alpha}{\sqrt{\frac{H_s}{g&space;\cdot&space;T_{om}^2}}}" title="\xi =\frac{tan \alpha}{\sqrt{\frac{H_s}{g \cdot T_{om}^2}}}" /></a>
</div>
<div style="text-align: center;">
<br /></div>
<div style="text-align: center;">
</div>
<div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="font-weight: normal;">Il
valore del numero di Irribarren dovrà essere confrontato con il
valore critico per distinguere i frangimenti </span></span></span></span></span><i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">plunging
</span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="font-weight: normal;">da
quelli </span></span></span></span></span><i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">surging:</span></span></span></span></i></div>
<div align="LEFT" style="margin-bottom: 0cm;">
<i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;"><br /></span></span></span></span></i></div>
<div align="LEFT" style="margin-bottom: 0cm;">
<i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">Van Der Meer per surging:</span></span></span></span></i></div>
<div align="LEFT" style="margin-bottom: 0cm;">
<i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;"><br /></span></span></span></span></i></div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=\frac{H_s}{\Delta&space;\cdot&space;D_{50}}=1&space;\cdot&space;P^{-0,13}&space;\cdot&space;\left(&space;\frac{S}{\sqrt{N}}&space;\right&space;)^{0,2}&space;\cdot&space;\sqrt{cot&space;(\alpha)}&space;\cdot&space;\xi_{0m}^P" target="_blank"><img src="http://latex.codecogs.com/png.latex?\frac{H_s}{\Delta&space;\cdot&space;D_{50}}=1&space;\cdot&space;P^{-0,13}&space;\cdot&space;\left(&space;\frac{S}{\sqrt{N}}&space;\right&space;)^{0,2}&space;\cdot&space;\sqrt{cot&space;(\alpha)}&space;\cdot&space;\xi_{0m}^P" title="\frac{H_s}{\Delta \cdot D_{50}}=1 \cdot P^{-0,13} \cdot \left( \frac{S}{\sqrt{N}} \right )^{0,2} \cdot \sqrt{cot (\alpha)} \cdot \xi_{0m}^P" /></a> </div>
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="font-weight: normal;"><br /></span></i></span></span></span>
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="font-weight: normal;">Van
der Meer </span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="font-weight: normal;">per
plunging:</span></span></span></span></span><br />
<br />
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=\frac{H_s}{\Delta&space;\cdot&space;D_{50}}=6,2&space;\cdot&space;P^{0,18}&space;\cdot&space;\left(&space;\frac{S}{\sqrt{N}}&space;\right&space;)^{0,2}&space;\cdot&space;\sqrt{cot&space;(\alpha)}&space;\cdot&space;\xi_{0m}^{-0,5}" target="_blank"><img src="http://latex.codecogs.com/png.latex?\frac{H_s}{\Delta&space;\cdot&space;D_{50}}=6,2&space;\cdot&space;P^{0,18}&space;\cdot&space;\left(&space;\frac{S}{\sqrt{N}}&space;\right&space;)^{0,2}&space;\cdot&space;\sqrt{cot&space;(\alpha)}&space;\cdot&space;\xi_{0m}^{-0,5}" title="\frac{H_s}{\Delta \cdot D_{50}}=6,2 \cdot P^{0,18} \cdot \left( \frac{S}{\sqrt{N}} \right )^{0,2} \cdot \sqrt{cot (\alpha)} \cdot \xi_{0m}^{-0,5}" /></a></div>
<br />
<br />
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Per
il dimensionamento dell'opera al piede si deve far riferimento alle
profondità di impianto e della cresta dell'opera stessa, il cui
rapporto deve essere in linea con i limiti imposte dalle normative.</span></span></span></div>
Radiuk Raikohttp://www.blogger.com/profile/16969685561223667013noreply@blogger.com0tag:blogger.com,1999:blog-8528715002040067567.post-67132231039476949222013-08-02T21:21:00.002+02:002013-08-02T21:21:35.023+02:00Diga a gettata<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;">Sono
opere di difesa portuale, possono essere distanziate o radicate a
terra, e creano uno specchio di acqua in quiete, evitando la
tracimazione. Vengono realizzate fino a circa 30 metri di profondità.
Nel calcolo di progettazione e verifica di queste strutture è
consentito solo agli Stati Limite Ultimi lo spostamento parziale o il
danneggiamento dei massi. Si devono verificare:</span><br />
<ul>
<li><div align="LEFT" style="margin-bottom: 0cm;">
Stabilità strutturale
della mantellata, dello strato filtro e dell'opera al piede;</div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
Risposta idraulica
della struttura, relativa agli effetti della struttura sul moto
ondoso;</div>
</li>
</ul>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<br /></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Sono
composte da:</span></span></span></div>
<ul>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<i>Massiccio di
coronamento: </i><span style="font-style: normal;">è un muro
paraonde in cemento armato non sempre presente in questo tipo di
struttura. Può essere impiegato come piattaforma di circolazione.</span></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<i>Mantellata esterna:
</i><span style="font-style: normal;">è quella </span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">rivolta
verso il mare aperto; può essere costituita da massi naturali
artificiali in calcestruzzo di forma convenzionale (tetrapodi,
core-loc, acropodi o dolos); la pendenza della struttura considerata
dipende dal tipo di materiale impiegato, in particolare è possibile
ottenere pendenze maggiori impiegando massi artificiali;</span></span></span></span></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="font-weight: normal;">Mantellata
interna:</span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">
per la protezione del lato porto; può essere estesa o meno a tutta
la scarpata e i massi che la compongono possono essere più piccoli
rispetto alla mantellata esterna in quanto sono soggetti a minori
sollecitazioni;</span></span></span></span></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="font-weight: normal;">Strato
filtro</span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">:
può essercene uno o di più, consentono la transizione delle
sollecitazioni tra la mantellata esterna e il nucleo centrale;</span></span></span></span></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="font-weight: normal;">Nucleo</span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">:
costituito da materiale di cava non selezionato granulometricamente
di media pezzatura;</span></span></span></span></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="font-weight: normal;">Opera
al piede: </span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">posta
o sul fondale o ad una quota elevata per contenere al piede la
mantellata esterna.</span></span></span></span></div>
<div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;"><br /></span></span></span></span></div>
<div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;"><br /></span></span></span></span></div>
<div class="separator" style="clear: both; text-align: center;">
<a href="http://3.bp.blogspot.com/-9uZVBPthtVg/UfwGH-KMKHI/AAAAAAAAF1E/K7VO2hmaZFI/s1600/Diga+a+gettata.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="152" src="http://3.bp.blogspot.com/-9uZVBPthtVg/UfwGH-KMKHI/AAAAAAAAF1E/K7VO2hmaZFI/s400/Diga+a+gettata.jpg" width="400" /></a></div>
<div class="separator" style="clear: both; text-align: center;">
<br /></div>
<div class="separator" style="clear: both; text-align: center;">
<br /></div>
<div class="separator" style="clear: both; text-align: center;">
</div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Definiamo
il <i>numero di stabilità</i>:</span></span></span></div>
<div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;"><br /></span></span></span></span></div>
</li>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=N_s=\frac{H}{\nabla&space;\cdot&space;D}" target="_blank"><span class="Apple-style-span" style="-webkit-text-decorations-in-effect: none; color: black;"></span></a><a href="http://www.codecogs.com/eqnedit.php?latex=N_s=\frac{H}{\nabla&space;\cdot&space;D}" target="_blank"><img src="http://latex.codecogs.com/gif.latex?N_s=\frac{H}{\nabla&space;\cdot&space;D}" title="N_s=\frac{H}{\nabla \cdot D}" /></a></div>
</ul>
<div style="text-align: center;">
<u>
<div align="LEFT" style="color: #0000ee; font-style: normal; font-weight: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Dove:</span></span></span></div>
<ul>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<i>H = </i><span style="font-style: normal;">è
l'onda di progetto;</span></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<i>D = </i><span style="font-style: normal;">è
una dimensione rappresentativa del materiale costituente l'opera;</span></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">Δ
= 1,6 per i massi naturali; è il </span></span></span></span></span></span><i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">coefficiente
di spinta di galleggiamento archimedeo;</span></span></span></span></span></i></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">N</span></span></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">s</span></span></span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">
= </span></span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">è
un valore compreso tra 1 e 4</span></span></span></span></span></span></div>
</li>
</ul>
</u></div>
Radiuk Raikohttp://www.blogger.com/profile/16969685561223667013noreply@blogger.com0tag:blogger.com,1999:blog-8528715002040067567.post-14636135155731577682013-08-02T21:18:00.000+02:002013-08-02T21:18:02.153+02:00Strutture a parete verticale
<br />
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Possono
essere sia strutture aderenti in prossimità di strade, ferrovie,
ecc..., sia strutture come le portuali. In tal caso vengono
realizzate quando la statistica degli eventi esterna è abbastanza
nota e quando non si ci trova in una condizione di frangimento. Si
realizzano a profondità che vanno dai 30 ai 40 metri di profondità,
dove cioè gettare una diga diventerebbe proibitivo per l'eccessivo
uso di materiale e nemmeno dove si verificano maree con escursioni
eccessive. La resistenza a ribaltamento alle azioni orizzontali è
dovuta sopratutto all'eccessivo peso, interviene nel moto ondoso
riflettendo completamente l'onda nel tratto di muro verticale,
generando di conseguenza un moto stazionario, con pressioni
schematizzabili con il modello di Saintflou. La loro struttura può
essere scomposta in 3 parti separate:</span></span></span></div>
<ul>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<i>Imbasamento</i><span style="font-style: normal;">:
gettata di tout-venant di cava protetto lato mare e lato monte da
una scarpata in massi, mentre la parte che vero la berma superiore
si crea una barriera realizzata in calcestruzzo livellati da
pietrame, chiamati </span><i>massi guardiani;</i></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<i>Infrastruttura: </i><span style="font-style: normal;">è
un corpo a sezione rettangolare formato da un cassone in cemento
armato, riempito di sabbia che supera il livello del mare di 1
metro;</span></div>
</li>
<li><i>Sovrastruttura:
</i><span style="font-style: normal;">viene realizzata con una
sezione ad L, con un muro avente il compito di essere paraonde, in
calcestruzzo armato, con un piano di calpestio sopra i 2,5 metri sul
livello del mare.</span></li>
</ul>
<div class="separator" style="clear: both; text-align: center;">
<a href="http://3.bp.blogspot.com/-Vioo_gDva0E/UfwFwBP_WSI/AAAAAAAAF08/GfFxhA9Tk1Q/s1600/Diga+verticale.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="158" src="http://3.bp.blogspot.com/-Vioo_gDva0E/UfwFwBP_WSI/AAAAAAAAF08/GfFxhA9Tk1Q/s400/Diga+verticale.jpg" width="400" /></a></div>
<div align="LEFT" style="margin-bottom: 0cm;">
<span style="font-style: normal;"><br /></span></div>
<div align="LEFT" style="margin-bottom: 0cm;">
<span style="font-style: normal;"><br /></span></div>
<div align="LEFT" style="margin-bottom: 0cm;">
<span style="font-style: normal;">
</span></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Una
variante di questo tipo di struttura è quella composita
orizzontalmente, che presenta la parte esterna protetta da una
massicciata. A differenza delle altre, questa ha un impatto visivo
minore.</span></span></span></div>
<br />
Radiuk Raikohttp://www.blogger.com/profile/16969685561223667013noreply@blogger.com0tag:blogger.com,1999:blog-8528715002040067567.post-29262596350368941622013-08-02T21:16:00.000+02:002013-08-02T21:16:03.924+02:00Tipologie di struttura<br />
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Queste
opere di difesa si dividono in due grandi categorie:</span></span></span></div>
<ul>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">Naturali</span></span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">,
spiagge o dune sono una vera e propria difesa per il litorale, visto
che il moto ondoso che colpisce queste strutture dissipano energia
con il frangimento; la duna impedisce al moto ondoso di agire
direttamente sul retrospiaggia, su di esse cresce spesso
vegetazione, e sono disposte parallelamente alla linea di riva.</span></span></span></span></span></span></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">Artificiali</span></span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">,
divisibili ancora in:</span></span></span></span></span></span></div>
</li>
<ul>
<li><div align="LEFT" style="font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>Soft:</i></span></span></span></div>
<ul>
<ul>
<li><div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Spiagge
artificiali, realizzate con sedimenti trasportati in mare, ma
sono molto soggette all'azione di erosione.</span></span></span></div>
</li>
</ul>
</ul>
</li>
<li><div align="LEFT" style="font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>Hard:</i></span></span></span></div>
</li>
<ul>
<ul>
<li><div align="LEFT" style="font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>Strutture
aderenti</i></span></span></span></div>
</li>
<li><div align="LEFT" style="font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>Strutture
longitudinali distanziate emergenti</i></span></span></span></div>
</li>
<li><div align="LEFT" style="font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>Strutture
longitudinali soffolte</i></span></span></span></div>
</li>
<li><span class="Apple-style-span" style="font-family: 'Times New Roman', serif;"><i>Strutture
di difesa trasversale (pennelli)</i></span><div align="LEFT" style="font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
</div>
</li>
</ul>
</ul>
</ul>
</ul>
<div>
<div align="LEFT" style="font-weight: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><u>Strutture
aderenti</u></i></span></span></span></div>
<div align="LEFT" style="font-weight: normal; margin-bottom: 0cm;">
<br />
</div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="font-family: Times New Roman, serif;"><span style="color: black;"><span style="font-size: small;">Sono
opere con il compito di mantenere fissa la linea di riva oltre che di
contenere i terreni, costruite parallelamente alla stessa linea di
riva e interessano la faccia della spiaggia ed anche la fascia di
riva. Sono maggiormente efficienti se l'attacco del moto ondoso è
frontale. Un esempio pratico che si può ricordare sono i </span></span><span style="color: black;"><span style="font-size: small;"><i>murazzi
</i></span></span><span style="color: black;"><span style="font-size: small;">usati in Veneto.</span></span></span></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="font-family: Times New Roman, serif;"><span style="color: black;"><span style="font-size: small;"><br /></span></span></span></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="font-family: Times New Roman, serif;"><span style="color: black;"><span style="font-size: small;">
</span></span></span></div>
<div align="LEFT" style="font-weight: normal; margin-bottom: 0cm;">
<span style="font-family: Times New Roman, serif;"><span style="color: black;"><span style="font-size: small;"><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><u>Strutture
longitudinali distanziate emergenti</u></i></span></span></span></span></span></span></div>
<span style="font-family: Times New Roman, serif;"><span style="color: black;"><span style="font-size: small;">
<div align="LEFT" style="font-weight: normal; margin-bottom: 0cm;">
<br />
</div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Sono
opere realizzati con massi naturali o artificiali, distanziati dalla
linea di riva e limitano la severità del moto ondoso. Si realizzano
con scogli naturali o artificiali. Si costruiscono per fronteggiare
gli attacchi frontali, ma gli attacchi non frontali possono causare
l'accumulo di materiale fino alla creazione di spiagge a sacca che
precedentemente alla loro installazione non erano presenti.</span></span></span></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><br /></span></span></span></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">
</span></span></span></div>
<div align="LEFT" style="font-weight: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><u>Strutture
longitudinali soffolte</u></i></span></span></span></span></span></span></div>
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">
<div align="LEFT" style="font-weight: normal; margin-bottom: 0cm;">
<br />
</div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Il
loro compito principale è quello di ridurre il moto ondoso, e tutto
quello che ne comporta. Essendo sommerse necessitano di un'opportuna
segnalazione per il pericolo che possono creare alle imbarcazioni.
Recentemente si sono molto studiate dal punto di vista ambientale,
difatti vengono anche realizzati con materiale naturale e vanno a
migliorare o creare una flora e fauna sottomarina che prima mancava.</span></span></span></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><br /></span></span></span></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">
</span></span></span></div>
<div align="LEFT" style="font-weight: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><u>Strutture
di difesa trasversale (pennelli)</u></i></span></span></span></span></span></span></div>
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">
<div align="LEFT" style="font-weight: normal; margin-bottom: 0cm;">
<br />
</div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Sono
tra le strutture più diffuse, sono ortogonali alla linea di riva e
radicate a terra, utilizzate per fronteggiare attacchi trasversali ed
limitare il trasporto longitudinale del materiale di fondo. Sono
costituite da massi naturali o artificiali, emerse o soffolte, che si
protraggono verso il mare fino all'altezza della zona dei
frangimenti. La distanza lungo la riva è di circa 2 o 3 volte la
loro lunghezza.</span></span></span></div>
</span></span></span></span></span></span></span></span></span></div>
Radiuk Raikohttp://www.blogger.com/profile/16969685561223667013noreply@blogger.com0tag:blogger.com,1999:blog-8528715002040067567.post-57657845457852104002013-08-02T21:13:00.003+02:002013-08-05T15:01:24.617+02:00STRUTTURE DI PROTEZIONE DEL LITORALE<br />
<div align="LEFT" style="line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><b><a href="http://costruzionimarittime.blogspot.it/2013/08/strutture-di-protezione-del-litorale.html">Strutture di protezione del litorale</a></b></span></span></span></div>
</div>
<ol>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><a href="http://costruzionimarittime.blogspot.it/2013/08/tipologie-di-struttura.html">Tipi di strutture di difesa e protezione del litorale</a></span></span></span></div>
</div>
<ol>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><a href="http://costruzionimarittime.blogspot.it/2013/08/strutture-parete-verticale.html">Strutture a parete verticale</a></span></span></span></div>
</div>
</li>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><a href="http://costruzionimarittime.blogspot.it/2013/08/diga-gettata.html">Diga a gettata</a></span></span></span></div>
</div>
</li>
</ol>
</li>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Dimensionamento di una diga a getta</span></span></span></div>
</div>
<ol>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><a href="http://costruzionimarittime.blogspot.it/2013/08/dimensionamento-della-della-mantellata.html">Dimensionamento della mantellata esterna</a></span></span></span></div>
</div>
</li>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Verifica della risposta idraulica</span></span></span></div>
</div>
</li>
</ol>
</li>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Dimensionamento strutture a cresta bassa o sommerse</span></span></span></div>
</div>
<ol>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Predimensionamento strutture a cresta bassa</span></span></span></div>
</div>
</li>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Dimensionamento strutture a cresta bassa dinamicamente stabili</span></span></span></div>
</div>
</li>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Dimensionamento strutture sommerse</span></span></span></div>
</div>
</li>
<li><div align="LEFT" style="font-style: normal; font-weight: normal; line-height: 20px; margin-bottom: 0cm; text-decoration: none;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Predimensionamento di una diga soffolta staticamente stabile</span></span></span></div>
</div>
</li>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Trasmissione del moto ondoso</span></span></span></div>
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><br /></span></span></span></div>
</div>
</li>
</ol>
</li>
</ol>
<br />
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Vengono
eseguite opere per difendere e proteggere i litorali, sopratutto
quando su questi c'è la presenza di strutture create dall'uomo che
esso stesso deve proteggere, o si vanno ad insediare nuovi
costruzioni. Inoltre si realizzano strutture che proteggano gli
arenili dall'erosione, sopratutto quando questi costituiscono una
risorsa.</span></span></span></div>
Radiuk Raikohttp://www.blogger.com/profile/16969685561223667013noreply@blogger.com0tag:blogger.com,1999:blog-8528715002040067567.post-7164236499636544062013-08-02T21:12:00.002+02:002013-08-02T21:12:56.824+02:00Trasporto solido longitudinale
<br />
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="font-family: Times New Roman, serif;"><span style="color: black;"><span style="font-size: small;">E'
dovuto al moto ondoso con attacco obliquo rispetto all'ortogonale
alle batimetriche. Le onde che vanno a frangere a riva creano delle
correnti stazionarie parallele alla stessa riva, </span></span><span style="color: black;"><span style="font-size: small;"><i>longshore
currents, </i></span></span><span style="color: black;"><span style="font-size: small;">creando
una corrente stazionaria che trascina via il materiale prendendolo
dal fondo; si determina il </span></span><span style="color: black;"><span style="font-size: small;"><i>drift
</i></span></span><span style="color: black;"><span style="font-size: small;">litoraneo. Si
può valutare con modelli matematici che forniscono il trasporto
potenziale rispetto al volume che può esser mosso. </span></span></span>
</div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<br />
</div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Si
può valutare quindi il trasporto longitudinale ottenendo un bilancio
per esempio su base annua; viene qui considerata un'altezza d'onda
significativa al largo, con un tempo di ritorno pari ad un anno. </span></span></span>
</div>
Radiuk Raikohttp://www.blogger.com/profile/16969685561223667013noreply@blogger.com0tag:blogger.com,1999:blog-8528715002040067567.post-7929073571356794792013-08-02T20:15:00.001+02:002013-08-02T20:15:48.835+02:00Profilo medio di equilibrio, profondità di chiusura<br />
<div align="LEFT" style="font-weight: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Le
caratteristiche del litorale sono fortemente influenzate dall’operato
dell’uomo, che con le sue modifiche può intervenire sia sulla
parte sommersa sia sulla parte emersa. La parte sommersa è in
generale acclive, con una pendenza definita come una variazione di
profondità rispetto al percorso, è sostanzialmente la tangente di
un angolo, che in genere ha valore pari a pochi punti percentuali,
spesso si fa riferimento al 2%.</span></span></span></div>
<div style="font-weight: normal; margin-bottom: 0cm;">
<span style="font-family: Times New Roman, serif;"><span style="color: black;"><span style="font-size: small;">In
prossimità della riva la pendenza del fondale tende a crescere,
avendo una concavità verso l’alto; quest’ultima, tuttavia, non è
uniforme, anche a causa delle </span></span><span style="color: black;"><span style="font-size: small;"><i>barre,
</i></span></span><span style="color: black;"><span style="font-size: small;">che sono
formazioni localizzate, o delle </span></span><span style="color: black;"><span style="font-size: small;"><i>barriere
coralline </i></span></span><span style="color: black;"><span style="font-size: small;">(formazioni
perenni). Si costruisce quindi un profilo medio di equilibrio che
deve rappresentare una determinata spiaggia. Questo è chiamato </span></span><span style="color: black;"><span style="font-size: small;"><span style="font-style: normal;">alla</span></span></span><span style="color: black;"><span style="font-size: small;"><i>
Dean. </i></span></span><span style="color: black;"><span style="font-size: small;"><span style="font-style: normal;">La
curva che lo rappresenta è detta </span></span></span><span style="color: black;"><span style="font-size: small;"><i>legge
di Dean, </i></span></span><span style="color: black;"><span style="font-size: small;"><span style="font-style: normal;">che
utilizza il parametro adimensionale </span></span></span><span style="color: black;"><span style="font-size: small;"><i>A,
</i></span></span><span style="color: black;"><span style="font-size: small;"><span style="font-style: normal;">definito
solo dal </span></span></span><span style="color: black;"><span style="font-size: small;"><i>d</i></span></span><span style="color: black;"><sub><span style="font-size: small;"><i>50</i></span></sub></span><span style="color: black;"><span style="font-size: small;"><i>:</i></span></span></span></div>
<div style="font-weight: normal; margin-bottom: 0cm;">
<span style="font-family: Times New Roman, serif;"><span style="color: black;"><span style="font-size: small;"><i><br /></i></span></span></span></div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=h=&space;\xi^{(\frac{2}{3})}&space;\cdot&space;A" target="_blank"><img src="http://latex.codecogs.com/png.latex?h=&space;\xi^{(\frac{2}{3})}&space;\cdot&space;A" title="h= \xi^{(\frac{2}{3})} \cdot A" /></a></div>
<br />
<br />
<div style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">Derivando
</span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="font-weight: normal;">h
</span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="font-weight: normal;">rispetto
a </span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">ξ
otteniamo la pende</span></span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">nza
del fondo:</span></span></span></span></span></span></div>
<div style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;"><br /></span></span></span></span></span></span></div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=\frac{dh}{d\xi}=\frac{2}{3}A&space;\cdot&space;\xi^{(-\frac{1}{3})}" target="_blank"><img src="http://latex.codecogs.com/png.latex?\frac{dh}{d\xi}=\frac{2}{3}A&space;\cdot&space;\xi^{(-\frac{1}{3})}" title="\frac{dh}{d\xi}=\frac{2}{3}A \cdot \xi^{(-\frac{1}{3})}" /></a>
</div>
<br />
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Il
profilo può essere diviso in due tratti, poiché la relazione di
Dean ci da una incongruenza, in quanto per ξ tendente a 0 si crea
una tangente verticale:</span></span></span></div>
<div align="LEFT" style="font-style: normal; margin-bottom: 0cm; text-decoration: none;">
<br /></div>
<div align="CENTER" style="font-weight: normal; margin-bottom: 0cm;">
<div class="separator" style="clear: both; text-align: center;">
<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;">Pendenza costante → se </span><a href="http://www.codecogs.com/eqnedit.php?latex=\xi&space;%3C&space;\overline{\xi}" style="margin-left: 1em; margin-right: 1em;" target="_blank"><img src="http://latex.codecogs.com/png.latex?\xi&space;<&space;\overline{\xi}" title="\xi < \overline{\xi}" /></a></div>
<div class="separator" style="clear: both; text-align: center;">
<br /></div>
<div class="separator" style="clear: both; text-align: center;">
</div>
<div align="CENTER" style="margin-bottom: 0cm;">
<div class="separator" style="clear: both; text-align: center;">
<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;"><span style="color: black;"><span style="font-size: small;"><span style="font-weight: normal;">Profilo alla Dean </span></span></span><span style="color: black;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">→ se </span></span></span></span></span></span><a href="http://www.codecogs.com/eqnedit.php?latex=\xi&space;%3E&space;\overline{\xi}" style="margin-left: 1em; margin-right: 1em;" target="_blank"><img src="http://latex.codecogs.com/png.latex?\xi&space;>&space;\overline{\xi}" title="\xi > \overline{\xi}" /></a></div>
<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;"><br /></span></div>
<br />
<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;"><br /></span></div>
<a href="http://www.codecogs.com/eqnedit.php?latex=\overline{\xi}" target="_blank"><img src="http://latex.codecogs.com/png.latex?\overline{\xi}" title="\overline{\xi}" /></a> <span class="Apple-style-span" style="font-family: 'Times New Roman', serif;">si
calcola imponendo che la pendenza arrivi al valore costante</span><br />
<div style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<br /></div>
<div style="font-weight: normal; margin-bottom: 0cm;">
<span style="font-family: Times New Roman, serif;"><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;">Definiamo
</span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;">profondità
di chiusura </span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;">il
limite verso il mare dove le onde non sono più in grado di provocare
variazioni di profondità rilevanti, tuttavia i sedimenti continuano
comunque a muoversi. Logicamente, tanto più è elevata l'altezza
d'onda tanto più la profondità di chiusura sarà distante da riva.
E' una grandezza che si misura su base annua attraverso la formula di
</span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;">Hallermaier,
</span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;">che
considera </span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;">H</span></i></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;">mo
</span></i></span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;">
come l'onda spettrale che viene superata 12 ore l'anno</span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;">:</span></i></span></span></span></span></div>
<div style="font-weight: normal; margin-bottom: 0cm;">
<span style="font-family: Times New Roman, serif;"><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><br /></span></i></span></span></span></span></div>
<div style="font-weight: normal; margin-bottom: 0cm;">
<span style="font-family: Times New Roman, serif;"><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><br /></span></i></span></span></span></span></div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=\frac{h_c}{H_{m0}}=2,28-68,5\frac{H_{m0}}{g&space;\cdot&space;T_p^2}" target="_blank"><img src="http://latex.codecogs.com/png.latex?\frac{h_c}{H_{m0}}=2,28-68,5\frac{H_{m0}}{g&space;\cdot&space;T_p^2}" title="\frac{h_c}{H_{m0}}=2,28-68,5\frac{H_{m0}}{g \cdot T_p^2}" /></a></div>
<div style="text-align: center;">
<br /></div>
<div style="text-align: center;">
</div>
<div style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">In
genere la profondità di chiusura è leggermente di più del doppio
rispetto all'onda spettrale che consideriamo.</span></span></span></div>
Radiuk Raikohttp://www.blogger.com/profile/16969685561223667013noreply@blogger.com0tag:blogger.com,1999:blog-8528715002040067567.post-59541429479601020332013-08-02T20:08:00.002+02:002013-08-02T20:08:38.231+02:00Trasporto litoraneo
<br />
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Rispetto
al fattore perturbante, che siano correnti correnti costiere, maree o
moto ondoso, ed alla dimensione dei sedimenti, il loro trasporto può
avvenire sia in sospensione che sul fondo. Si considerano due
principali tipologie di trasporto:</span></span></span></div>
<ul>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">Trasversale
alla linea di riva</span></span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">:
in caso di attacco frontale e non frontale;</span></span></span></span></span></span></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">Longitudinale
alla linea di riva: </span></span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">in
caso di attacco non frontale;</span></span></span></span></span></span></div>
</li>
</ul>
<ol>
<ol>
<div align="CENTER" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><u><b>Trasporto
trasversale alla linea di riva</b></u></i></span></span></span></div>
</ol>
</ol>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">La
dinamica del litorale varia a livello stagionale in relazione alle
mareggiate. Durante l'inverno inizialmente si ha un'asportazione del
materiale più fine, poi quelli di dimensioni maggiori che vengono
depositati nella zona più vicina alla linea di riva, mentre quelle
più fini rimangono più a lungo in sospensione andando a depositarsi
al largo. Questo avviene in maniera continua provocando l'erosione
del litorale, almeno nella stagione invernale, mentre nella stagione
estiva, si può recuperare il materiale fino depositato al largo.
Tuttavia la presenza dell'uomo e l'antropizzazione delle coste
interferisce con questi processi, provocando sia azioni erosive per
le quali è necessario pensare alla realizzazione di opere di
protezione del litorale.</span></span></span></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<br />
</div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;">Oltre
alla creazione della </span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;">barre</span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;">
longitudinali durante il periodo invernale, si creano anche delle
</span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;">berme,
</span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;">che
si presentano come larghe spiagge sopratutto nel periodo estivo dove
le onde sono meno severe. Il materiale fino si accumula sulla
spiaggia a spese della berma che si irripidisce fino ad arrivare ad
un profilo di equilibrio stabile dipendente dal diametro del grano
del sedimento.</span></span></span></span></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<br />
</div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Il
trasporto si può valutare partendo dall'analisi delle tensioni
tangenziali al fondo; si utilizzano formule mutuate dalle condizioni
di moto permanente, o diversamente con formule globali che si basano
sullo scostamento del profilo dalla condizione di equilibrio.</span></span></span></div>
Radiuk Raikohttp://www.blogger.com/profile/16969685561223667013noreply@blogger.com0tag:blogger.com,1999:blog-8528715002040067567.post-48504530166007501892013-08-02T20:07:00.001+02:002013-08-05T13:37:41.742+02:00PROCESSI COSTIERI: Definizione di litorale e della sua dinamica - classificazione dei sedimenti<br />
<div align="LEFT" style="line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><b><a href="http://costruzionimarittime.blogspot.it/2013/08/processi-costieri-definizione-di.html">Processi costieri</a></b></span></span></span></div>
</div>
<ol>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm; text-decoration: none;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><a href="http://costruzionimarittime.blogspot.it/2013/08/processi-costieri-definizione-di.html">Definizione di litorale e della sua dinamica - classificazione dei sedimenti</a></span></div>
</div>
</li>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm; text-decoration: none;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><a href="http://costruzionimarittime.blogspot.it/2013/08/trasporto-litoraneo.html">Trasporto litoraneo</a></span></span></span></div>
</div>
<ol>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><a href="http://costruzionimarittime.blogspot.it/2013/08/trasporto-litoraneo.html">Trasporto trasversale alla linea di riva</a></span></span></span></div>
</div>
</li>
</ol>
</li>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><a href="http://costruzionimarittime.blogspot.it/2013/08/profilo-medio-di-equilibrio-profondita.html">Profilo medio di equilibrio, profondità di chiusura</a></span></div>
</div>
</li>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><a href="http://costruzionimarittime.blogspot.it/2013/08/trasporto-solido-longitudinale.html">Trasporto solido longitudinale</a></span></span></span></div>
</div>
</li>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Trasporto solido trasversale</span></span></span></div>
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><br /></span></span></span></div>
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><br /></span></span></span></div>
</div>
</li>
</ol>
<br />
<div align="LEFT" style="font-weight: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Per
<i>litorale </i><span style="font-style: normal;">si intende quella
zona che comprende sia la spiaggia emersa che quella sommersa divise
dalla linea di </span><i>riva</i><span style="font-style: normal;">,
soggetta a moto ondoso e correnti. Viene divise in 3 zone:</span></span></span></span></div>
<ul>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">Backshore
</span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="font-weight: normal;">o
</span></span></span></span></span><i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">retro
spiaggia, </span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="font-weight: normal;">la
zona compresa tra la linea di riva e il punto in cui si ha un cambio
fisiografico o cresce la vegetazione; </span></span></span></span></span>
</div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">Nearshore,
</span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="font-weight: normal;">è
la zona tra la linea di riva e il punto da essa più distante dove
si verificano i frangimenti. Viene suddivisa in:</span></span></span></span></span></div>
<ul>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">Breaker
Zone</span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="font-weight: normal;">,
dove si verificano i frangimenti;</span></span></span></span></span></div>
</li>
<li><div align="LEFT" style="font-weight: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>Surf
Zone;</i></span></span></span></div>
</li>
<li><div align="LEFT" style="font-weight: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>Swash
Zone;</i></span></span></span></div>
</li>
</ul>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">Offshore,
</span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="font-weight: normal;">che
va dalla zona di frangimento al limite della piattaforma
continentale.</span></span></span></span></span></div>
<div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="font-weight: normal;"><br /></span></span></span></span></span></div>
<div class="separator" style="clear: both; text-align: center;">
<a href="http://4.bp.blogspot.com/-L3cWGp87npw/Ufv09Xk-DxI/AAAAAAAAF0s/poyLjQP0_PI/s1600/Littoral+zone.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="138" src="http://4.bp.blogspot.com/-L3cWGp87npw/Ufv09Xk-DxI/AAAAAAAAF0s/poyLjQP0_PI/s400/Littoral+zone.jpg" width="400" /></a></div>
<div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="font-weight: normal;">
</span></span></span></span></span></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><br /></span></span></span></span></span></span></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Si
possono classificare le spiagge in base alla loro pendenza:</span></span></span></span></span></span></div>
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">
<ul>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">Dissipative:
</span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="font-weight: normal;">debole
pendenza, con sabbie fini ed un ampia zona di frangenti;</span></span></span></span></span></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">Intermedie:
</span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="font-weight: normal;">caratterizzata
da una pendenza moderata;</span></span></span></span></span></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">Riflettenti:
</span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="font-weight: normal;">molto
ripide, i sedimenti sono costituiti da ciottoli, le onde tendono a
frangersi vicino a riva.</span></span></span></span></span></div>
</li>
</ul>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm;">
<br /></div>
<div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="font-weight: normal;">Il
materiale dei sedimenti con cui è costituita la spiaggia interagisce
direttamente con il moto ondoso solamente se questo non è coesivo.
Quindi si classificano i sedimenti in maniera probabilistica in base
al diametro medio del singolo granulo in </span></span></span></span></span><i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">mm</span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="font-weight: normal;">.
</span></span></span></span></span>
</div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm;">
<br /></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Si
usa una scala logaritmica invece che lineare per considerare tutti i
granuli, visto che in una normale spiaggia si troverebbe un ampia
gamma:</span></span></span></div>
</span></span></span></li>
</ul>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=\Phi&space;=-&space;log_2(d)" target="_blank"><img src="http://latex.codecogs.com/png.latex?\Phi&space;=-&space;log_2(d)" title="\Phi =- log_2(d)" /></a></div>
<div style="text-align: center;">
<br /></div>
<div style="text-align: center;">
</div>
<div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="font-weight: normal;">Il
logaritmo è in base 2 perché si ci riferisce ad un diametro di 2
mm. Questa funzione</span></span></span></span></span><i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-weight: normal;">
</span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">Φ</span></span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">
è possibile rappresentarla con una funzione di distribuzione
gaussiana, non adimensionalizzata, riferita al valore medio invece
che allo 0. Oltre al diametro ma meno usata è la </span></span></span></span></span></span><i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">velocità
di caduta libera in acqua </span></span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">che
è diversa di quella della caduta in aria. Si usa la </span></span></span></span></span></span><i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">deviazione
standard </span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">σ</span></span></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">Φ
</span></span></span></span></sub></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">o
il </span></span></span></span></span></span><i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">coefficiente
di selezione (o sorting</span></span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">),
per misurare la dispersione di </span></span></span></span></span></span><i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">
</span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">Φ.
</span></span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">Detto
questo, la classificazione dei sedimenti viene fatta valutando:</span></span></span></span></span></span></div>
<ul>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">Densità
</span></span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">ρ
;</span></span></i></span></span></span></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">Velocità
di caduta in acqua </span></span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">w
;</span></span></i></span></span></span></div>
</li>
<li><div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Porosità;</span></span></span></div>
</li>
<li><div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Grado
di saturazione;</span></span></span></div>
</li>
</ul>
Radiuk Raikohttp://www.blogger.com/profile/16969685561223667013noreply@blogger.com0tag:blogger.com,1999:blog-8528715002040067567.post-6148953193938261892013-08-02T19:47:00.001+02:002013-08-02T19:47:31.148+02:00Trasferimento del clima ondoso verso le basse profondità
<br />
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">I
rilievi sugli stati di mare vengono fatti a profondità infinita al
largo delle coste, pertanto, per progettare opere sui litorali
dovremmo conoscere come il moto ondoso si trasferisce verso riva.
Nelle onde regolari, considerando i processi di rifrazione e di
shoaling, riusciamo a definire l'evoluzione dell'altezza dell'onda
verso riva, ma trascuriamo le dissipazioni dovute a eventuali
frangimenti, il comportamento o l'interazione con altre armoniche
dello spettro. Dopo una certa profondità <i>h, </i>riconsideriamo il
fenomeno di rifrazione e di shoaling. Dal largo verso riva, nella
propagazione dell'onda irregolare, dovremmo confrontare le altezze
d'onda con quelle di frangimento, attraverso le f<i>ormule di Goda</i>,
imponendo come coefficiente <i>A=0,12.</i></span></span></span></div>
Radiuk Raikohttp://www.blogger.com/profile/16969685561223667013noreply@blogger.com0tag:blogger.com,1999:blog-8528715002040067567.post-31833734594707444582013-08-02T19:39:00.002+02:002013-08-02T19:39:52.753+02:00Metodi di previsione a lungo termine<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Permettono
di considerare stati di mare rappresentati da un'altezza d'onda
caratteristica, ed un loro relativo tempo di ritorno </span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>T</i></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>r
</i></span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>.
</i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">I
diversi tipi di modello che esistono su questo metodo di previsioni
si accomunano di due ipotesi:</span></span></span><br />
<ul>
<li><div align="LEFT" style="font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>Omogeneità
dei dati;</i></span></span></span></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">Indipendenza
statistica, </span></span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">cioè
che ogni evento è considerato indipendente dagli altri;</span></span></span></span></span></span></div>
</li>
</ul>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<br /></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">I
dati raccolti vengono approssimati per adattarsi a una funzione di
probabilità. Per raccogliere i dati esistono diversi metodi:</span></span></span></div>
<ul>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">Metodo
P.O.T.:</span></span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">
vengono scelti i dati da prendere in esame, considerando solo la
mareggiata con stati di mare con un'altezza d'onda caratteristica
superiore a una certa soglia, imposta dal progettista. E' il metodo
più in uso;</span></span></span></span></span></span></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">Criterio
dei dati completi: </span></span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">si
considerano i dati a disposizione nella loro interezza. Questo
criterio anche se più ampio, ha la limitazione che i valori più
bassi di altezza dell'onda pesano nell'andamento della curva
risultante;</span></span></span></span></span></span></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">Metodo
A.M.</span></span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">:
si considerato i dati dei massimi annuali.</span></span></span></span></span></span></div>
</li>
</ul>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<br /></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Le
funzioni di probabilità adottate sono principalmente due:</span></span></span></div>
<ul>
<li><div align="LEFT" style="font-weight: normal; margin-bottom: 0cm;">
<i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;">Weilbull:
</span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;">3
parametri fondamentali;</span></span></span></span></span></div>
</li>
<li><div align="LEFT" style="font-weight: normal; margin-bottom: 0cm;">
<i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;">Gumbel:
</span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;">2
parametri fondamentali;</span></span></span></span></span></div>
</li>
</ul>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
</div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<br /></div>
<div align="LEFT" style="font-weight: normal; margin-bottom: 0cm;">
<i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;">Boccotti
</span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;">ha
utilizzato una funzione di distribuzione di tipo Weilbull a 2
parametri, per il mar Mediterraneo adatto sia in relazione a mari
</span></span></span></span></span><i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;">omnidirezionali</span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;">
che </span></span></span></span></span><i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;">direzionali</span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;">,
considerando solo come parametri </span></span></span></span></span><i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;">u
</span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;">e
</span></span></span></span></span><i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;">w</span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;">.</span></span></span></span></span></div>
<div align="CENTER" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<br /></div>
<div align="CENTER" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Direzionale:</span></span></span></div>
<div align="CENTER" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;"><br /></span></div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=Q(H_{m0})=exp&space;\left[&space;-&space;\left(&space;\frac{H_{m0}}{w_\alpha}&space;\right&space;)^u&space;\right&space;]-exp&space;\left[&space;-&space;\left(&space;\frac{H_{m0}}{w_\beta}&space;\right&space;)^u&space;\right&space;]" target="_blank"><img src="http://latex.codecogs.com/png.latex?Q(H_{m0})=exp&space;\left[&space;-&space;\left(&space;\frac{H_{m0}}{w_\alpha}&space;\right&space;)^u&space;\right&space;]-exp&space;\left[&space;-&space;\left(&space;\frac{H_{m0}}{w_\beta}&space;\right&space;)^u&space;\right&space;]" title="Q(H_{m0})=exp \left[ - \left( \frac{H_{m0}}{w_\alpha} \right )^u \right ]-exp \left[ - \left( \frac{H_{m0}}{w_\beta} \right )^u \right ]" /></a></div>
<div style="text-align: center;">
<br /></div>
<div style="text-align: center;">
</div>
<div align="CENTER" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Omnidirezionale</span></span></span></div>
<div align="CENTER" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><br /></span></span></span></div>
<div align="CENTER" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><br /></span></span></span></div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=Q(H_{m0})=exp&space;\left[&space;-&space;\left(&space;\frac{H_{m0}}{w}&space;\right&space;)^u&space;\right&space;]" target="_blank"><img src="http://latex.codecogs.com/png.latex?Q(H_{m0})=exp&space;\left[&space;-&space;\left(&space;\frac{H_{m0}}{w}&space;\right&space;)^u&space;\right&space;]" title="Q(H_{m0})=exp \left[ - \left( \frac{H_{m0}}{w} \right )^u \right ]" /></a> </div>
<br />
Dove:
Wα Wβ sono i parametri che tengono conto della direzionalità. Boccotti ha individuati 16 parametri che tendono conto della direziona, uno per ogni settore di traversia.
Definiamo la densità di probabilità che si verifichi uno stato di mare tramite:<br />
<br />
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=p(H_{m0})=&space;\frac{-dQ}{dH_{m0}}" target="_blank"><img src="http://latex.codecogs.com/png.latex?p(H_{m0})=&space;\frac{-dQ}{dH_{m0}}" title="p(H_{m0})= \frac{-dQ}{dH_{m0}}" /></a></div>
<div style="text-align: center;">
<br /></div>
<div style="text-align: center;">
</div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Boccotti
ha permesso di definire:</span></span></span></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<br /></div>
<ul>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">Tempo
di ritorno dello stato di mare:</span></span></span></span></span></span></div>
</li>
</ul>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=T_r(H_{m0})=\frac{D_m&space;(H_{m0})&space;}{Q(H_{m0})+H_{m0}&space;\cdot&space;p(H_{m0})}" target="_blank"><img src="http://latex.codecogs.com/png.latex?T_r(H_{m0})=\frac{D_m&space;(H_{m0})&space;}{Q(H_{m0})+H_{m0}&space;\cdot&space;p(H_{m0})}" title="T_r(H_{m0})=\frac{D_m (H_{m0}) }{Q(H_{m0})+H_{m0} \cdot p(H_{m0})}" /></a></div>
<div align="LEFT" style="margin-bottom: 0cm;">
<ul>
<li><span class="Apple-style-span" style="font-family: 'Times New Roman', serif;">Persistenza
dello stato di mare nella mareggiata:</span></li>
</ul>
</div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=D(H_{m0})=Q(H_{m0})&space;\cdot&space;T_r(H_{m0})" target="_blank"><img src="http://latex.codecogs.com/png.latex?D(H_{m0})=Q(H_{m0})&space;\cdot&space;T_r(H_{m0})" title="D(H_{m0})=Q(H_{m0}) \cdot T_r(H_{m0})" /></a></div>
<div style="text-align: center;">
</div>
<div style="margin-bottom: 0cm; text-align: left;">
</div>
<ul>
<li><span class="Apple-style-span" style="font-family: 'Times New Roman', serif;">Durata
della mareggiata: </span></li>
</ul>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=D_m=b_{10}\cdot&space;(1,11-0,11&space;\frac{H_{m0}}{a_{10}})" target="_blank"><img src="http://latex.codecogs.com/png.latex?D_m=b_{10}\cdot&space;(1,11-0,11&space;\frac{H_{m0}}{a_{10}})" title="D_m=b_{10}\cdot (1,11-0,11 \frac{H_{m0}}{a_{10}})" /></a></div>
<div style="text-align: center;">
<br /></div>
<div style="text-align: center;">
<br /></div>
<div class="separator" style="clear: both; text-align: center;">
<a href="http://4.bp.blogspot.com/-Nc8b_jQtXi0/Ufvussa7aQI/AAAAAAAAF0c/9kNoO_5v6A4/s1600/Mareggiata+Boccotti.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="282" src="http://4.bp.blogspot.com/-Nc8b_jQtXi0/Ufvussa7aQI/AAAAAAAAF0c/9kNoO_5v6A4/s400/Mareggiata+Boccotti.jpg" width="400" /></a></div>
<div style="text-align: center;">
<br /></div>
Radiuk Raikohttp://www.blogger.com/profile/16969685561223667013noreply@blogger.com0tag:blogger.com,1999:blog-8528715002040067567.post-63807244921882196922013-08-02T19:19:00.001+02:002013-08-02T19:19:30.044+02:00Modello RLS<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;">E'
un modello di previsione a breve termine indiretto, su una profondità
infinita che lega le condizioni di vento allo stato di mare e
verifica le condizioni dello spettro Jonswap medio. Si devono
considerare:</span><br />
<ul>
<li><div align="LEFT" style="font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>U
→ costante</i></span></span></span></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">t
</span></span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">→
</span></span></span></span></span></span><i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">gt/U</span></span></span></span></span></i></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">x
→ gx/U</span></span></i></span></span></span><span style="color: black;"><sup><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">2</span></span></i></span></span></sup></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">
</span></span></i></span></span></span>
</div>
</li>
</ul>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<br /></div>
<div align="LEFT" style="font-style: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">Tramite
l'uso di questi parametri possiamo confrontare </span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">x
</span></span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">e
</span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">t
</span></span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">con
i rispettivi valori critici, per poter così determinare il regime
del bacino marino:</span></span></span></span></span><br />
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;"><br /></span></span></span></span></span></div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=\frac{g&space;\cdot&space;t_{cr}}{U}=21,88&space;\cdot&space;\left(&space;\frac{gx}{U^2}&space;\right&space;)^{0,797}" target="_blank"><img src="http://latex.codecogs.com/png.latex?\frac{g&space;\cdot&space;t_{cr}}{U}=21,88&space;\cdot&space;\left(&space;\frac{gx}{U^2}&space;\right&space;)^{0,797}" title="\frac{g \cdot t_{cr}}{U}=21,88 \cdot \left( \frac{gx}{U^2} \right )^{0,797}" /></a></div>
<br />
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=\frac{g&space;\cdot&space;x_{cr}}{U}=19'000" target="_blank"><img src="http://latex.codecogs.com/png.latex?\frac{g&space;\cdot&space;x_{cr}}{U}=19'000" title="\frac{g \cdot x_{cr}}{U}=19'000" /></a></div>
<div style="text-align: center;">
<br /></div>
<div style="text-align: center;">
</div>
<div align="LEFT" style="font-style: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">E'
possibile ricavare un valore di altezza d'onda caratteristica a breve
termine, ed un periodo associato alla stessa onda. Le formule
relative al regime stazionario con </span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">t
>t</span></span></i></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">cr</span></span></i></span></span></sub></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">
</span></span></span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">:</span></span></span></span></span></div>
<div align="LEFT" style="font-style: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;"><br /></span></span></span></span></span></div>
<div align="LEFT" style="font-style: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;"><br /></span></span></span></span></span></div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=\frac{g&space;\cdot&space;H_{m0}}{U^2}=0,00125&space;\left(&space;\frac{gx}{U^2}&space;\right&space;)^{0,55}" target="_blank"><img src="http://latex.codecogs.com/png.latex?\frac{g&space;\cdot&space;H_{m0}}{U^2}=0,00125&space;\left(&space;\frac{gx}{U^2}&space;\right&space;)^{0,55}" title="\frac{g \cdot H_{m0}}{U^2}=0,00125 \left( \frac{gx}{U^2} \right )^{0,55}" /></a> </div>
<br />
<div style="text-align: center;">
</div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=\frac{g&space;\cdot&space;T_{Hm0}}{U}=0,287&space;\left(&space;\frac{gx}{U^2}&space;\right&space;)^{0,33}" target="_blank"><img src="http://latex.codecogs.com/png.latex?\frac{g&space;\cdot&space;T_{Hm0}}{U}=0,287&space;\left(&space;\frac{gx}{U^2}&space;\right&space;)^{0,33}" title="\frac{g \cdot T_{Hm0}}{U}=0,287 \left( \frac{gx}{U^2} \right )^{0,33}" /></a></div>
Radiuk Raikohttp://www.blogger.com/profile/16969685561223667013noreply@blogger.com0tag:blogger.com,1999:blog-8528715002040067567.post-69289830013746815972013-08-02T19:11:00.000+02:002013-08-02T19:11:31.062+02:00Bilancio energetico dell'area di generazione<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;">E'
un metodo che lega il vento allo stato di mare, si basa sulla
determinazione della densità dello stato di mare e si procede
analizzando alcune variabili fondamentali. Possiamo scrivere un
dipendenza funzionale:</span><br />
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><br /></span></span></span></div>
<div style="margin-bottom: 0cm; text-align: center;">
<span style="color: black; font-style: normal; font-weight: normal; text-decoration: none;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">E = f ( </span></span></span><span class="Apple-style-span" style="font-family: 'Times New Roman', serif; font-style: normal; font-weight: normal; text-decoration: none;"><i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">U</span></span></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">10 </span></span></span></span></sub></span></i></span><span class="Apple-style-span" style="font-family: 'Times New Roman', serif; font-style: normal; font-weight: normal; text-decoration: none;"><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">, </span></span></span></span></span></span></span>t , x , <span class="Apple-style-span" style="font-family: 'Times New Roman', serif;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">ρ , g )</span></span></i></span></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><br /></span></span></span></div>
<div align="LEFT" style="font-style: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">
</span></span></span></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Dove:</span></span></span></span></span></span></div>
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">
</span></span></span>
<br />
<ul style="font-weight: normal;"><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">
<li><div align="LEFT" style="margin-bottom: 0cm;">
<i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">U</span></span></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">10
</span></span></span></span></sub></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">:
velocità del vento misurata a 10 m sul livello del mare;</span></span></span></span></span></span></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">t
</span></span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">:
tempo</span></span></span></span></span></span></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">x
</span></span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">:
estensione del fetch</span></span></span></span></span></span></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">ρ</span></span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">
: densità del fluido</span></span></span></span></span></span></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">g
</span></span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">:
accelerazione di gravità </span></span></span></span></span></span>
</div>
</li>
</span></span></span></ul>
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">
</span></span></span>
<br />
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;">Possiamo
fare un'analisi dimensionale riconducendo la dipendenza funzionale di
E ad altre tre grandezze fondamentali che esprimono tutte le
variabili in funzioni di queste:</span></div>
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">
</span></span></span>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><br /></span></span></span></div>
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">
<div align="LEFT" style="font-style: normal; margin-bottom: 0cm; text-decoration: none;">
</div>
<div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><b>Parametro
di durata:</b></span></span></span></span></span></div>
</span></span></span><br />
<div style="text-align: center;">
</div>
<div style="text-align: left;">
<div class="separator" style="clear: both; text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=t^x=\frac{gt}{U_{10}}" style="margin-left: 1em; margin-right: 1em; text-align: center;" target="_blank"><img src="http://latex.codecogs.com/png.latex?t^x=\frac{gt}{U_{10}}" title="t^x=\frac{gt}{U_{10}}" /></a></div>
<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;"><b><br /></b></span>
<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;"><b>Parametro di fetch:</b></span></div>
<div style="text-align: left;">
<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;"><b><br /></b></span></div>
<div style="text-align: left;">
<div class="separator" style="clear: both; text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=x^x=\frac{gx}{U_{10}^2}" style="margin-left: 1em; margin-right: 1em;" target="_blank"><img src="http://latex.codecogs.com/png.latex?x^x=\frac{gx}{U_{10}^2}" title="x^x=\frac{gx}{U_{10}^2}" /></a></div>
<div class="separator" style="clear: both; text-align: center;">
<br /></div>
<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;"><b>Parametro di energia:</b></span></div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=E^x=\frac{g&space;\cdot&space;E}{\rho&space;\cdot&space;U_{10}^4}" target="_blank"><img src="http://latex.codecogs.com/png.latex?E^x=\frac{g&space;\cdot&space;E}{\rho&space;\cdot&space;U_{10}^4}" title="E^x=\frac{g \cdot E}{\rho \cdot U_{10}^4}" /></a>
</div>
<div style="text-align: center;">
<br /></div>
<div style="text-align: center;">
</div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Risulta
quindi una dipendenza funzionale della densità di energia
adimensionale in base ai parametri di fetch e di durata:</span></span></span></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<br />
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=E^x=f(t^x,x^x)" target="_blank"><img src="http://latex.codecogs.com/png.latex?E^x=f(t^x,x^x)" title="E^x=f(t^x,x^x)" /></a>
</div>
<div style="text-align: center;">
<br /></div>
<div style="text-align: center;">
</div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Possiamo
distinguere 3 diversi regimi:</span></span></span></div>
<ul>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">Transitorio</span></span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">:
l'energia scambiata col vento è in funzione sia del fetch che della
durata. L'energia dovuta al vento, meno quella dissipata, incrementa
la densità </span></span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">E
</span></span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">di
energia locale;</span></span></span></span></span></span></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">Stazionario</span></span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">:
dipende solo dal parametro di fetch, visto che il parametro di
durata si può non considerare se il vento spira per un tempo
superiore ad un certo </span></span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">t</span></span></i></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">cr
</span></span></i></span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">.
</span></span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">Non
incrementa l'energia locale, ma attiva un flusso di energia lungo
l'estensione del fetch su cui conserva il suo valore;</span></span></span></span></span></span></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">Completamente
sviluppato</span></span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">:
in inglese </span></span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">F.A.S.
</span></span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">Acronimo
di </span></span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">Fully
Arisen Sea, </span></span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">il
parametro di energia rimane costante, indipendente dagli altri due
parametri, quando parte da una condizione stazionaria, con il fetch
sufficiente esteso, maggiore di x</span></span></span></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">cr</span></span></span></span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">.</span></span></span></span></span></span></div>
</li>
</ul>
<div align="CENTER" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<br />
</div>
</div>
Radiuk Raikohttp://www.blogger.com/profile/16969685561223667013noreply@blogger.com0tag:blogger.com,1999:blog-8528715002040067567.post-521586972771879532013-08-02T18:59:00.003+02:002013-08-02T18:59:57.426+02:00Modelli di previsioni
<br />
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Si
intendono modelli parametrici che legano gli stati di mare ad alcuni
tempi di ritorno. Il clima di un bacino marino è definito attraverso
la conoscenza di:</span></span></span></div>
<ul>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">Periodo
di ritorno T</span></span></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">r
</span></span></span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">:</span></span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">
l'intervallo medio di ripetitività di eventi uguali, ovvero di
eventi ondosi di altezza </span></span></span></span></span></span><i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">H</span></span></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">m0</span></span></span></span></sub></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">
e di periodo </span></span></span></span></span></span><i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">T</span></span></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">Hm0</span></span></span></span></sub></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">;</span></span></span></span></span></span></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">Probabilità
di accadimento P</span></span></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">A
</span></span></span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">:
</span></span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">di
eventi ondosi con fissati valori di </span></span></span></span></span></span><i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">T</span></span></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">r</span></span></span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">,
</span></span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">durante
un tempo legato alle condizioni di progetto, legato alla vita utile
dell'opera;</span></span></span></span></span></span></div>
</li>
</ul>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
</div>
<ol>
<ol>
<div align="CENTER" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif; font-size: large;"><i><u><b>Modelli
di previsione a breve termine</b></u></i></span></span></div>
</ol>
</ol>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Per
la realizzazione di questo tipo di modelli esistono tre metodi
diversi:</span></span></span></div>
<ul>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">Metodi
diretti: </span></span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">servono
osservazioni visuali che forniscono rilievi dell'onda significativa,
ovvero osservazioni strumentali che rilevano la superficie di
ondulazione dove tramite metodi statistici si riesce a calcolare
l'altezza spettrale;</span></span></span></span></span></span></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">Metodi
indiretti</span></span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">:
basati sul bilancio energetico dell'area di generazione, individuano
l'onda significativa, o </span></span></span></span></span></span><i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">spettrale</span></span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">,
con i dati forniti del vento a profondità infinita con la creazione
di modelli matematici;</span></span></span></span></span></span></div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">Metodi
misti: </span></span></span></span></span></i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">i
dati forniti dai metodi indiretti vengono valutati sul campo, quindi
mischiandoli con i dati dei metodi diretti;</span></span></span></span></span></span></div>
</li>
</ul>
<br />
Radiuk Raikohttp://www.blogger.com/profile/16969685561223667013noreply@blogger.com0tag:blogger.com,1999:blog-8528715002040067567.post-62916858964806410532013-08-02T18:58:00.001+02:002013-08-02T18:58:27.384+02:00Descrizione statistica delle onde irregolari<div align="LEFT" style="font-weight: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Si
possono individuare delle onde associate allo stato di mare, rispetto
agli spostamenti nel tempo </span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>η(t)
</i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">,
tramite il metodo chiamato </span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>zero
up crossing </i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">o
in alternativa </span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>zero
down crossing.</i></span></span></span></div>
<div align="LEFT" style="font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<br /></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">In
questa maniera riusciamo a numerare le oscillazioni, scartandone i
disturbi ed ottenendo valori di altezza </span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>H
</i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">e
del periodo </span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>T.
</i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Adimensionalizzando
le coppie di valori </span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>H
</i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">e
</span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>T
</i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">otteniamo:</span></span></span><br />
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><br /></span></span></span>
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><br /></span></span></span></div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=T^*=\frac{T}{T_p}" target="_blank"><img src="http://latex.codecogs.com/png.latex?T^*=\frac{T}{T_p}" title="T^*=\frac{T}{T_p}" /></a> <a href="http://www.codecogs.com/eqnedit.php?latex=H^*=\frac{H}{\sigma_\eta}" target="_blank"><img src="http://latex.codecogs.com/png.latex?H^*=\frac{H}{\sigma_\eta}" title="H^*=\frac{H}{\sigma_\eta}" /></a></div>
<div style="text-align: center;">
<br /></div>
<div style="text-align: center;">
<br /></div>
<div style="text-align: center;">
</div>
<div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">Con
tale associazione dei parametri alle varie oscillazioni, otteniamo
una nuvola di punti che rappresentano le onde, questa evidenzia la
tendenza delle onde più alte ad avere come periodo prossimo a </span></span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">T</span></span></i></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">p</span></span></i></span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">=(T</span></span></i></span></span></span><span style="color: black;"><sup><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">*</span></span></i></span></span></sup></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">
=1).</span></span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">La
densità massima di oscillazione si avrà in un intorno di </span></span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">H</span></span></i></span></span></span><span style="color: black;"><sup><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">*</span></span></i></span></span></sup></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">=2</span></span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">
</span></span></span></span></span></span>
</div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<br />
</div>
<div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">Se
accettiamo un'ipotesi di distribuzione tipo </span></span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">Rayleigh</span></span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">
possiamo individuare la distribuzione statistica delle altezze
d'onda.</span></span></span></span></span></span></div>
<div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;"><br /></span></span></span></span></span></span></div>
<div align="LEFT" style="margin-bottom: 0cm;">
<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;"><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">Prima
di questi modelli si descrivevano i fenomeni di moto ondoso mediante
un approccio statistico, considerando lo stato di mare riferito
all'altezza media del terzo delle onde più alte che si registravano,
</span></span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">H</span></span></i></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">1/3</span></span></i></span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">
</span></span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">detta
</span></span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">one
highest third. </span></span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">Il
collegamento tra questi due approcci può avvenire se e solo se viene
accettata la distribuzione statistica delle altezze d'onda secondo
Rayleigh per la quale </span></span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">H</span></span></i></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">1/3</span></span></i></span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">
coincide con </span></span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">H</span></span></i></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">m0</span></span></i></span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">.
Tale ipotesi rende cautelativa la nostra analisi, perché abbiamo la
probabilità di superamento di onde alte maggiore rispetto al vero. </span></span></span></span></span></span></span></div>
Radiuk Raikohttp://www.blogger.com/profile/16969685561223667013noreply@blogger.com0tag:blogger.com,1999:blog-8528715002040067567.post-5323080813409739432013-08-02T18:53:00.000+02:002013-08-02T18:53:09.993+02:00Descrizione spettrale degli stati di mare su profondità infinita<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Nell'approccio
spettrale si considera la scomposizione delle oscillazioni come somma
di infinite componenti armoniche elementari, cioè onde regolari di
ampiezza diversa, frequenza diversa e sfasate tra loro di una fase
casuale uniformemente distribuita tra 0 e 2 π. Queste armoniche
individuano le frequenze con maggiore contributo energetico. </span></span></span>
</div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Considerando
una distribuzione continua, definiamo lo </span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>spettro
di frequenze </i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><b>S(f)
</b></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">la
cui area parziale sottesa tra </span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>f</i></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>n
</i></span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>e
f</i></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>n</i></span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>+df
</i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">rappresenta
a meno di </span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>
</i></span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>ρg
</i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">la
densità di energia dell'onda elementare con frequenza </span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>f</i></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>n
</i></span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>.
</i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Avremo
quindi:</span></span></span></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><br /></span></span></span></div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=E=&space;\rho&space;g&space;\int_{0}^{+&space;\infty}&space;S(\eta)d\eta" target="_blank"><img src="http://latex.codecogs.com/png.latex?E=&space;\rho&space;g&space;\int_{0}^{+&space;\infty}&space;S(\eta)d\eta" title="E= \rho g \int_{0}^{+ \infty} S(\eta)d\eta" /></a></div>
<div style="text-align: center;">
<br /></div>
<div style="text-align: center;">
</div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Definiamo
il momento di ordine </span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>r-esimo:</i></span></span></span><br />
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><br /></i></span></span></span></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<div class="separator" style="clear: both; text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=m_r=&space;\int_{0}^{+&space;\infty}&space;f^r&space;S(f)df" style="margin-left: 1em; margin-right: 1em;" target="_blank"><img src="http://latex.codecogs.com/png.latex?m_r=&space;\int_{0}^{+&space;\infty}&space;f^r&space;S(f)df" title="m_r= \int_{0}^{+ \infty} f^r S(f)df" /></a></div>
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><br /></i></span></span></span></div>
<div align="LEFT" style="font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;"><i>
</i></span><br />
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;"><i>
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">In
particolare avremo:</span></span></span></i></span></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;"><i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><br /></span></span></span></i></span></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;"><i><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><br /></span></span></span></i></span></div>
</div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=m_0=&space;\int_{0}^{+&space;\infty}&space;S(f)df=&space;\sigma^2_\eta" target="_blank"><img src="http://latex.codecogs.com/png.latex?m_0=&space;\int_{0}^{+&space;\infty}&space;S(f)df=&space;\sigma^2_\eta" title="m_0= \int_{0}^{+ \infty} S(f)df= \sigma^2_\eta" /></a></div>
<div style="text-align: center;">
<br /></div>
<div style="text-align: center;">
<br /></div>
<div style="text-align: center;">
</div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Dove:
</span></span></span>
</div>
<ul>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">m</span></span></i></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">0</span></span></i></span></span></sub></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">
</span></span></span></span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">è
un momento di ordine 0 coincidente con la varianza del processo.</span></span></span></span></span></span></div>
</li>
</ul>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<br /></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Introduciamo
grandezze spettrali e parametri:</span></span></span></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><br /></span></span></span></div>
<div align="LEFT" style="margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">
</span></span></span></div>
<ul><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">
<li><div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black; font-style: normal; font-weight: normal;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">Periodo
di picco: </span></span></i></span></span></span><b><i>T<sub>p</sub>=1/f<sub>p </sub></i></b><span style="color: black; font-style: normal; font-weight: normal;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;"> con </span></span></span></span></span></span><span style="color: black; font-style: normal; font-weight: normal;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">f</span></span></i></span></span></span><span style="color: black; font-style: normal; font-weight: normal;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">p</span></span></i></span></span></sub></span><span style="color: black; font-style: normal; font-weight: normal;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">=f
</span></span></i></span></span></span><span style="color: black; font-style: normal; font-weight: normal;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">al
massimo dello spettro unimodale</span></span></span></span></span></span></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
</div>
</li>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black; font-style: normal; font-weight: normal;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">Periodo
medio: </span></span></span></span></span></span><b><i>T<sub>m</sub>=
m<sub>0</sub>/m<sub>1 </sub>= 0,8 T<sub>p</sub></i></b></div>
<div align="LEFT" style="margin-bottom: 0cm;">
<b><i><sub><br /></sub></i></b></div>
<div align="LEFT" style="margin-bottom: 0cm;">
<b><i><sub>
</sub></i></b></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<b><i>
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Il
contributo energetico apportato dalla varie armoniche è contenuto
tra quelle che vengono definite come:</span></span></span></i></b></div>
<i>
</i></li>
<li><i><span class="Apple-style-span" style="font-style: normal;"><i><ul style="display: inline !important;">
<li style="display: inline !important; font-weight: bold;"><div align="LEFT" style="display: inline !important; margin-bottom: 0cm;">
<div style="display: inline !important;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">frequenza
di taglio inferiore → f</span></span></i></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">1 </span></span></i></span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">=
0,4 f</span></span></i></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">p</span></span></i></span></span></sub></span></div>
</div>
</li>
</ul>
</i></span></i></li>
<ul><i>
</i></ul>
<li><i><span class="Apple-style-span" style="font-style: normal;"><i><ul style="display: inline !important;">
<li style="display: inline !important;"><div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black; font-weight: bold;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;"> frequenza
di taglio</span></span></i></span></span></span><span style="color: black; font-weight: bold;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">
</span></span></span></span></span></span><span style="color: black; font-weight: bold;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">superiore
→ f</span></span></i></span></span></span><span style="color: black; font-weight: bold;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">2 </span></span></i></span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">= (3/5 ) fp</span></span></i></span></span></span><span class="Apple-style-span" style="font-style: normal;"><i></i></span></div>
<div align="LEFT" style="margin-bottom: 0cm;">
<br /></div>
<div style="text-align: -webkit-left;">
<br />
<div align="LEFT" style="font-style: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">Le
prime trattazioni avevano alcune limitazioni visto che non
consideravano né l'età del mare né la direzionalità delle
armoniche, detta </span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">spreading.
</span></span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">Solo
con lo spettro </span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">Jonswap,
</span></span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">modificato
inserendo il parametro di direzionalità </span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">θ</span></span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">
da </span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">Pierson,
s</span></span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">i
è arrivati ad una modellazione che permette di descrivere lo stato
di mare con uno spettro direzionale parametrico, al quale si può
associare un'onda rappresentativa regolare che ha un'altezza d'onda
pari a </span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">H</span></span></i></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">m0</span></span></i></span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">=4
σ</span></span></i></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">η</span></span></i></span></span></sub></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">
</span></span></span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">relativo
al periodo di </span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">T</span></span></i></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">Hm0. </span></span></i></span></span></sub></span></div>
</div>
</li>
</ul>
</i></span></i></li>
</span></span></span></ul>
Radiuk Raikohttp://www.blogger.com/profile/16969685561223667013noreply@blogger.com0tag:blogger.com,1999:blog-8528715002040067567.post-53683654767070430962013-08-02T14:02:00.002+02:002013-08-05T00:45:26.383+02:00Onde irregolari: Stato di mare su profondità infinita<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;"></span><br />
<div align="LEFT" style="font-family: Times; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;"><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><b><a href="http://costruzionimarittime.blogspot.it/2013/08/onde-irregolari-stato-di-mare-su.html">Onde irregolari</a></b></span></span></span></span></div>
</div>
<ol style="font-family: Times;">
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;"><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><a href="http://costruzionimarittime.blogspot.it/2013/08/onde-irregolari-stato-di-mare-su.html">Stato di mare su profondità infinite</a></span></span></span></span></div>
</div>
</li>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;"><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><a href="http://costruzionimarittime.blogspot.it/2013/08/descrizione-spettrale-degli-stati-di.html">Descrizione spettrale degli stati di mare su profondità infinita</a></span></span></span></span></div>
</div>
</li>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;"><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><a href="http://costruzionimarittime.blogspot.it/2013/08/descrizione-statistica-delle-onde.html">Descrizione statistica delle onde irregolari</a></span></span></span></span></div>
</div>
</li>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;"><span style="color: black;"><a href="http://costruzionimarittime.blogspot.it/2013/08/modelli-di-previsioni.html">Modelli di previsione</a></span></span></div>
</div>
<ol>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;"><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><a href="http://costruzionimarittime.blogspot.it/2013/08/modelli-di-previsioni.html">Modelli di previsione a breve termine</a></span></span></span></span></div>
</div>
<ol>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;"><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><a href="http://costruzionimarittime.blogspot.it/2013/08/bilancio-energetico-dellarea-di.html">Bilancio energetico dell’area di generazione</a></span></span></span></span></div>
</div>
</li>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;"><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><a href="http://costruzionimarittime.blogspot.it/2013/08/modello-rls.html">Modello RLS</a></span></span></span></span></div>
</div>
</li>
</ol>
</li>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;"><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><a href="http://costruzionimarittime.blogspot.it/2013/08/metodi-di-previsione-lungo-termine.html">Modelli di previsione a lungo termine</a></span></span></span></span></div>
</div>
</li>
</ol>
</li>
<li><div align="LEFT" style="font-weight: normal; line-height: 20px; margin-bottom: 0cm;">
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;"><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><a href="http://costruzionimarittime.blogspot.it/2013/08/trasferimento-del-clima-ondoso-verso-le.html">Trasferimento del clima ondoso verso le basse profondità</a></span></span></span></span></div>
</div>
</li>
</ol>
<br />
<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;"><br /></span>
<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;">Osservando
le onde nella realtà, si è visto che esse non si presentano come
regolari e progressive. Si devono fare alcune ipotesi sullo stato di
mare descritto attraverso le superfici di ondulazione nel tempo in un
punto preso per poter trattare questo argomento:</span><br />
<ul>
<li><div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Stazionario;</span></span></span></div>
</li>
<li><div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Ergodico;</span></span></span></div>
</li>
<li><div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Gaussiano;</span></span></span></div>
</li>
<li><div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">A
media nulla.</span></span></span></div>
</li>
</ul>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<br /></div>
<div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">Possiamo
quindi descrivere questo fenomeno in maniera statistica dalla sola
varianza </span></span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">σ</span></span></i></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">n</span></span></i></span></span></sub></span><span style="color: black;"><sup><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">2</span></span></i></span></span></sup></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">
, che fa riferimento alle oscillazioni di un singolo stato di mare,
questo perché nelle ipotesi di lavoro fatte in precedenza si è
stabilito che per l'ergodicità che caratterizza il sistema possiamo
non dover considerare una popolazione di dati. Considerando una
distribuzione gaussiana adimensionale, è possibile definire queste
grandezze:</span></span></span></span></span></span></div>
<div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;"><br /></span></span></span></span></span></span></div>
<div align="LEFT" style="margin-bottom: 0cm;">
<br />
<ul>
<li><span class="Apple-style-span" style="font-family: 'Times New Roman', serif;">Densità di probabilità:</span></li>
</ul>
</div>
<div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;"><br /></span></span></span></span></span></span></div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=p(\eta^*)=\frac{1}{\sqrt{2\pi}}exp\left(-&space;\frac{\eta^{*2}}{2}&space;\right&space;)" target="_blank"><img src="http://latex.codecogs.com/png.latex?p(\eta^*)=\frac{1}{\sqrt{2\pi}}exp\left(-&space;\frac{\eta^{*2}}{2}&space;\right&space;)" title="p(\eta^*)=\frac{1}{\sqrt{2\pi}}exp\left(- \frac{\eta^{*2}}{2} \right )" /></a></div>
<div style="text-align: center;">
<br /></div>
<div style="text-align: left;">
</div>
<ul>
<li>Probabilità cumulata:</li>
</ul>
<div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=P(\eta^*)=\int_{-\infty&space;}^{\eta}p(\eta^*)&space;d\eta^*" target="_blank"><img src="http://latex.codecogs.com/png.latex?P(\eta^*)=\int_{-\infty&space;}^{\eta}p(\eta^*)&space;d\eta^*" title="P(\eta^*)=\int_{-\infty }^{\eta}p(\eta^*) d\eta^*" /></a>
</div>
<div style="text-align: center;">
<br /></div>
<div style="text-align: center;">
</div>
<ul>
<li style="text-align: left;">Probabilità di superamento:</li>
</ul>
<div style="text-align: left;">
<br /></div>
</div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=Q(\eta^*)=\int_{&space;\eta}^{\infty}p(\eta^*)&space;d\eta^*" target="_blank"><img src="http://latex.codecogs.com/png.latex?Q(\eta^*)=\int_{&space;\eta}^{\infty}p(\eta^*)&space;d\eta^*" title="Q(\eta^*)=\int_{ \eta}^{\infty}p(\eta^*) d\eta^*" /></a>
</div>
<div style="text-align: left;">
</div>
<ul>
<li>Densità di energia dello stato di mare:</li>
</ul>
<div>
<br /></div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=E=\rho&space;g&space;\sigma_{\eta}]" target="_blank"><img src="http://latex.codecogs.com/png.latex?E=\rho&space;g&space;\sigma_{\eta}]" title="E=\rho g \sigma_{\eta}]" /></a>
</div>
<div style="text-align: center;">
<br /></div>
<div style="text-align: center;">
</div>
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<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Dove con</span></span></span><span class="Apple-style-span" style="font-family: 'Courier New', monospace; font-size: 15px;"><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"> </span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;">σ</span></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;">η</span></span></span></sub></span><span style="color: black;"><sup><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;">
</span></span></span></sup></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;">la
radice della varianza (deviazione standard)</span></span></span></span></span></div>
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<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><br /></span></span></span></div>
<a href="http://www.codecogs.com/eqnedit.php?latex=\eta^*=\frac{\eta}{\sigma_\eta}" target="_blank"><img src="http://latex.codecogs.com/png.latex?\eta^*=\frac{\eta}{\sigma_\eta}" title="\eta^*=\frac{\eta}{\sigma_\eta}" /></a>
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<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">La
descrizione nel tempo è fatta rispetto ad un punto fissato nello
spazio, inoltre si considera che il comportamento statistico possa
ritenersi omogeneo nell'intorno della posizione di rilevamento.</span></span></span></div>
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<a href="http://3.bp.blogspot.com/-zthrnmw0Yik/UfufjoxUC_I/AAAAAAAAF0E/P2SAtp0tgjg/s1600/Stato+di+mare+su+profondita%CC%80+infinita+1.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="206" src="http://3.bp.blogspot.com/-zthrnmw0Yik/UfufjoxUC_I/AAAAAAAAF0E/P2SAtp0tgjg/s320/Stato+di+mare+su+profondita%CC%80+infinita+1.jpg" width="320" /></a></div>
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<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><br /></span></span></span></div>
Radiuk Raikohttp://www.blogger.com/profile/16969685561223667013noreply@blogger.com0tag:blogger.com,1999:blog-8528715002040067567.post-60897230969205203902013-08-02T13:34:00.000+02:002013-08-02T13:34:04.761+02:00Variazione del livello medio rispetto al livello di quiete
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<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-decoration: none;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Il
moto ondoso che procede verso riva tenderà a differenziare il
livello medio dal livello di quiete di una quantità </span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>Δ</i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">,
questo per compensare l'effetto della variazione del radiation
stress </span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>S</i></span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>xx
</i></span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">con
la pressione idrostatica</span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>.
</i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Quindi
il livello medio (</span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>set-down</i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">)
si ridurrà dalla sezione al largo fino a quella di frangimento, dove
l'abbassamento risulterà massimo. Dalla sezione di frangimento fino
ad arrivare a riva, il livello medio salirà, fino a superare il
livello di quiete. A riva arriverà al livello massimo (</span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>set-up</i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">).
Questo fenomeno si apprezza sia con le onde regolari sia con quelle
irregolari.</span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>
</i></span></span></span>
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<a href="http://2.bp.blogspot.com/-hrVy1I1vXv4/UfuY_OAVXZI/AAAAAAAAFz0/uYX1vP9Vwj8/s1600/Variazione+del+livello+medio+rispetto+al+livello+di+quiete+2.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="315" src="http://2.bp.blogspot.com/-hrVy1I1vXv4/UfuY_OAVXZI/AAAAAAAAFz0/uYX1vP9Vwj8/s400/Variazione+del+livello+medio+rispetto+al+livello+di+quiete+2.jpg" width="400" /></a></div>
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<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><br /></span></span></span></div>
Radiuk Raikohttp://www.blogger.com/profile/16969685561223667013noreply@blogger.com0tag:blogger.com,1999:blog-8528715002040067567.post-85005466889823211212013-08-02T13:31:00.001+02:002013-08-02T13:31:46.127+02:00Moti tridimensionali<span class="Apple-style-span" style="font-family: 'Times New Roman', serif;">Le
grandezze indispensabili per definite un'onda al largo sono 3:</span><br />
<ul>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">Altezza
</span></span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">H</span></span></i></span></span></span></div>
</li>
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<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;"><span style="font-weight: normal;">Periodo
</span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">T</span></span></i></span></span></span></div>
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<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Angolo
di attacco</span></span></span></div>
</li>
</ul>
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<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Nella
progressione verso riva, possiamo quindi considerare:</span></span></span></div>
<ul>
<li><div align="LEFT" style="margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">Un
fondale con poca inclinazione da poterlo schematizzare come
orizzontale a tratti, con le batimetriche rettilinee e parallele, si
viene quindi a generare un'onda bidimensionale la cui oscillazione
sarà al tempo t: </span></span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">η(x,y)</span></span></i></span></span></span></div>
</li>
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<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="text-decoration: none;"><span style="font-weight: normal;">Se
non consideriamo il fondale bidimensionale, che genera un'onda
tridimensionale, avremo che l'oscillazione che dipenderà da
</span></span></span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><span style="font-weight: normal;">η(x,z,t)</span></span></i></span></span></span></div>
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</li>
</ul>
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<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><b>Diffrazione</b></span></span></span></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;">Un
moto che incontra un ostacolo tende a riflettersi parzialmente, a
frangersi ed a essere assorbito, dopodiché inizierà il fenomeno
della </span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;">diffrazione.
</span></i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;">Questo
fenomeno si sovrappone allo shoaling, quindi nella realtà risulta
essere molto più complesso perché si combina con altri effetti.</span></span></span></span></div>
<div align="LEFT" style="font-style: normal; font-weight: normal; margin-bottom: 0cm;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span style="text-decoration: none;">Viene
definito il </span></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;">coefficiente
di diffrazione:</span></i></span></span></span></div>
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<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><br /></span></i></span></span></span></div>
<div style="font-style: normal; font-weight: normal; margin-bottom: 0cm; text-align: left;">
<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i><span style="text-decoration: none;"><br /></span></i></span></span></span></div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=k_{difr}=\frac{H_{locale}}{H_{arrivo}}" target="_blank"><img src="http://latex.codecogs.com/png.latex?k_{difr}=\frac{H_{locale}}{H_{arrivo}}" title="k_{difr}=\frac{H_{locale}}{H_{arrivo}}" /></a>
</div>
Radiuk Raikohttp://www.blogger.com/profile/16969685561223667013noreply@blogger.com0tag:blogger.com,1999:blog-8528715002040067567.post-87491038353506427612013-08-02T13:29:00.001+02:002013-08-02T13:29:19.202+02:00Attacco non frontale: Rifrazione<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Si
verifica quando la direzione in cui si muovono le onde, cioè le
</span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>ortogonali
d'onda, </i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">
non si mantengono a distanza costante nella direzione della
propagazione, mutando la loro inclinazione dalla profondità infinita
fino a riva. Questa variazione di direzione è ottenuta da condizioni
geometriche secondo la </span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>legge
di Snell</i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">.
Viene definito un </span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>coefficiente
di rifrazione </i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">ottenuto
eguagliando il flusso energetico tra due ortogonali d'onda
consecutive. Ricordando che α</span></span></span><span style="color: black;"><sub><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">0
</span></span></sub></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">è
l'angolo di attacco non frontale, mentre </span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><i>α</i></span></span></span><span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">
si calcola con le legge dell'ottica geometrica di Snell:</span></span></span><br />
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<span style="color: black;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><br /></span></span></span></div>
<div style="text-align: center;">
<a href="http://www.codecogs.com/eqnedit.php?latex=\frac{sin&space;(\alpha_0)}{c_0}=\frac{sin&space;(\alpha)}{c}" target="_blank"><img src="http://latex.codecogs.com/png.latex?\frac{sin&space;(\alpha_0)}{c_0}=\frac{sin&space;(\alpha)}{c}" title="\frac{sin (\alpha_0)}{c_0}=\frac{sin (\alpha)}{c}" /></a></div>
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<a href="http://www.codecogs.com/eqnedit.php?latex=\alpha=arcsin\left[&space;\left&space;(\frac{c}{c_0}\right)&space;\cdot&space;sen(\alpha_0)\right]" target="_blank"><img src="http://latex.codecogs.com/png.latex?\alpha=arcsin\left[&space;\left&space;(\frac{c}{c_0}\right)&space;\cdot&space;sen(\alpha_0)\right]" title="\alpha=arcsin\left[ \left (\frac{c}{c_0}\right) \cdot sen(\alpha_0)\right]" /></a></div>
Radiuk Raikohttp://www.blogger.com/profile/16969685561223667013noreply@blogger.com0