浪通過圓弧面帷幕牆式防波堤之研究

Wave Interactions with Quadrant Front-Face Pile Supported Breakwater

莊世璿(Shih-Hsuan Chuang) ； 莊貿鈞(Mao-Chun Chuang) ； 楊喻傑(Yu-Chieh Yang) ； 岳景雲(Ching-Yun Yueh)

《海洋工程學刊》 14卷3期 (2014/09) Pp. 149-160

https://doi.org/10.6266/JCOE.2014.1403.02

摘要

本文利用多領域邊界元素法（Multi-domain BEM）建立一套數值模式，探討波浪正向入射多列圓弧面帷幕牆式防波堤其消波特性，包含反射率、透過率、能量損失及相對溯升高之研究。圓弧面帷幕牆式防波堤是將上半部向海側原為不透水矩形斷面結構改為透水四分之一圓弧面，而下半部是由群樁支撐取代原有的拋石部分組合而成，希望能結合上半部為透水圓弧面，與下半部為群樁之各自優點，充分發揮其消能效果，向岸側為一不透水垂直面結構，可作為船舶停靠，適用於保護較小港區。數值計算時首先決定樁柱列數、樁柱群相對高度，探討向浪側圓弧面及底板為透水或不透水之差異，經由數值計算結果發現反射率變化要比透過率變化來的明顯；而且反射率值會隨著無因次週波數之增加而增加；向浪側及底板為透水配置時，可增加消能效果及大幅降低波浪作用於結構物相對溯升高。

關鍵字

圓弧面帷幕牆式防波堤 ； 反射 ； 溯升高

並列摘要

The purpose of the present study is to present a numerical model (Multi-domain BEM) developed to predict the hydrodynamic performance characteristics of normal incident wave with multiple-row quadrant front-face pile supported breakwaters. The breakwater under consideration here is a quadrant front-face supported on piles, in which piles replace the rubble mound and the quadrant on the lee side is replaced with a rectangular section. This is expected to give the combined benefits of both the quadrant and pile breakwater. The leeward side of the top portion with a vertical face would facilitate the berthing of vessels. That may be a useful alternative to gravity-type breakwaters, for protecting small craft harbors. Numerical results show that the variation of reflection coefficient with wavenumber is more significant compared with the variation of transmission coefficient with wavenumber. The reflection coefficient increase with increase in dimensionless wavenumber. The front face and bottom slab plate of the permeable breakwater increases the effect of energy dissipation and reduces the run-up. The purpose of the present study is to present a numerical model (Multi-domain BEM) developed to predict the hydrodynamic performance characteristics of normal incident wave with multiple-row quadrant front-face pile supported breakwaters. The breakwater under consideration here is a quadrant front-face supported on piles, in which piles replace the rubble mound and the quadrant on the lee side is replaced with a rectangular section. This is expected to give the combined benefits of both the quadrant and pile breakwater. The leeward side of the top portion with a vertical face would facilitate the berthing of vessels. That may be a useful alternative to gravity-type breakwaters, for protecting small craft harbors. Numerical results show that the variation of reflection coefficient with wavenumber is more significant compared with the variation of transmission coefficient with wavenumber. The reflection coefficient increase with increase in dimensionless wavenumber. The front face and bottom slab plate of the permeable breakwater increases the effect of energy dissipation and reduces the run-up.

並列關鍵字

quadrant front-face pile supported breakwaters ； reflection ； run-up