本文係以理論配合試驗研究在海堤前方裝置一消波護坦，此一護坦底部為一不透水底板，目的在防止海砂被淘刷，其上部則為透水性材料，目的在於消殺波浪，降低海堤坡面之溯上以達到降低海堤高度之目的。本文經理論配合試驗研究三種不同孔隙率之消波護坦，其結果驗證Twu, et al.(2001) 之理論，即當摩擦係數約大於1之情況下，孔隙率愈大者，其降低海堤溯上高之效果愈佳，若將護坦長度增加或潛沒水深減少，孔隙率大者其降低溯上高之效果也愈顯著，若採用此一高消波性之護坦，除具有防止海堤堤趾被淘刷之功能外，尚能有效降低海堤高度。

　This study is to investigate the reducing effect on the wave run-up over the seawall by a porous apron .The apron is designed to serve two major purposes. One of them is to protect the seabed at the toe of the seawall from scouring. The other is to attenuate the incoming waves. To achieve this, the bottom of the apron is made of a solid plate. And upper part of it must be a porous structure. Three types of porous media have been used as the material for the upper part of the apron. They are referred to as material A, B and C, and their porosities are 0.9, 0.77 and 0.45, respectively. Then experimental tests are conducted using three depths of submergence, four different apron lengths and two different seawall slopes. It is concluded that the apron with larger porosity would raise smaller wave run-up over the seawall. Moreover, as the depth of submergence decreases, the length increases, the wave run-up will be reduced.

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