Experimental Study on the Wave Energy Dissipation Due to the Porous Quaywall Structures

• Main Authors: Wu-An Chang, 張武安
• Other Authors: Sung-Shan Hsiao
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/20262870605628320208

碩士 === 國立臺灣海洋大學 === 河海工程學系 === 95 === In this research, the focus is basically on the use of physical model to seek for reflection and energy dissipation under porous quay-wall. Under the physical model the main attraction of design is on gravity matters, which by using scaling ratio of Froude number to similitude the model and the wave criterion. Thus, base on the purpose, the model was therefore by changing the porous quay-wall into n=0.4、0.5、0.6, selecting the quay-wall thickness on b/h=0.6、0.77、0.95 and assuming the characteristic height of impermeable bottom with qh=0、0.3h. This combination conditions was then generated by input wave condition of non-dimensional frequency . By the flume tests measurement, analysis of wave shape was suggested to use the two-point method by Goda & Suzuki (1976). On conclusion, influences of the smallest reflection under different period was on the porous quay-wall (n) and the characteristic length (b/h、qh). As to the long period condition which is not easy to dissipate, this study focus on the porous ratio of n=0.6, quay-wall thickness under b/h=0.95 and impermeable bottom with qh=0.3h to cope the matter. Result shows the best energy dissipation solution of 98.12 % on non-dimensional frequency with which the reflection ratio is Kr=0.115.