波浪作用於親水性海堤之研究

Abstract

本文假設等水深之海堤為連續對稱且入射波為正向，因此可將三維連續性海堤簡化為二維。應用數值方法（邊界元素法）來探討無限延伸且連續形狀的親水性海堤於有限水深處受波浪作用所生的水位及壓力變化之研究。並運用正交函數展開法之解析解來驗證邊界元素法的準確性。而本文所模擬的海堤突出結構物之形狀共分三種，分別是：矩形、三角形、橢圓形。當入射波之波長大於2倍渠道寬時，海堤僅引致單一正向反射波；反之，海堤引致的反射波除了正向反射波外，還包括了斜向反射波。

The seawalls are assumed to be symmetrical and to continue at a uniform depth, and the wave direction is assumed to be right, and so this study is assumed to be a two dimensional linear water wave theory. The boundary element method is developed and applied to study the pressure and water line created by waves forces on the continuous and infinite promenade seawalls with a uniform depth. The accuracy of the present numerical model is proved by comparing the numerical model results with analytical results from applying the orthogonal function. Three types of prominent structures are selected for study, namely：rectangular, triangular, and elliptic. When the incident wavelength is smaller than the double width of the channel, only one normal reflection occurs. Otherwise, the normal and inclined reflections occurred simultaneously.