长周期波作用下强输沙率海岸岛式防波堤平面设计

General layout design of coastal island-type breakwater with strong sediment transport rate under long period wave

针对长周期涌浪作用下强输沙率海岸的码头总平面设计问题,以贝宁湾某配套工作船码头项目为例,采用岛式防波堤方案。利用波浪数模试验、泥沙冲淤数模试验等方法验证岛堤平面设计的合理性,解决了平面布局问题。基于日本规范对船舶竖向位移进行初步计算,并利用水动力有限元分析方法对规范计算结果进行对比验证,解决了长周期波条件下的航道设计水深问题。结果表明:(1)在长周期波、强输沙率条件下,波浪掩护决定口门朝向、岛堤轴线等布局条件;(2)岛堤与破波线距离、进港航道水深是决定岛式防波堤平面位置的控制性因素,须合理论证和计算;(3)日本规范计算方法较适用于长周期波条件下的航道水深设计,建议在类似工程中使用。

In view of the general layout design problem of the coastal wharf with strong sediment transport rate under long-period swells,taking a supporting boat wharf project in the Benin Bay as an example,the island breakwater scheme is adopted.The rationality of the general layout design of the island breakwater is verified by using wave numerical model test and sediment scouring and silting numerical model test,so as to solve the general layout problem.A preliminary calculation of the ship's vertical displacement is carried out based on the Japanese code,and the hydrodynamic finite element analysis method is used to compare and verify the calculation results of the code,which solves the problem of channel design water depth under the condition of long-period waves.The results show that:(1)Under the conditions of long-period wave and strong sediment transport rate,the wave protection determines the layout conditions such as the harbor entrance orientation and breakwater axis.(2)The distance between the breakwater and the surf zone and the water depth of the approach channel are both the controlling factors to determine the plan position of the breakwater,which must be reasonably justified and calculated.(3)The Japanese code calculation method is more suitable for the design of channel water depth under the condition of long period waves,and it is recommended to be used in similar projects.