中日直立式双板桩防波堤设计方法比较研究

A Comparative Study on the Design Methods of Vertical Double Sheet Pile Breakwater Between China and Japan

直立式双板桩防波堤是一种对深水软土地基有较强适应性的防波堤结构,但是目前尚无系统的设计方法。本文以某外海深水直立式双板桩防波堤为例,分别采用国内规范和日本规范给出的方法计算直立式双板桩防波堤的入土深度和桩身内力。结果表明,中日规范在直立式双板桩防波堤的设计中均有一定的局限性:对于国内规范,当堤顶宽度较小时,其墙后主动土压力的计算会与实际情况有较大差别;对于日本规范,当堤顶宽度较大时,墙后填土产生的抵抗弯矩不符合实际情况。由此,对直立式双板桩防波堤的设计,建议同时采用中日两种计算方法进行设计并相互验证,共同拟定合理的结构断面。

The vertical double sheet pile breakwater is a breakwater structure that has a good adaptability to the deep-water soft soil foundation.However,there has been no systematical method for designing such a breakwater by now.By taking one of the deep-water vertical double sheet pile breakwaters as an example,the penetrating depth and the pile internal force of the vertical double sheet pile breakwater are calculated according to the Chinese and the Japanese specifications respectively.The calculation results show that both the Chinese and the Japanese specifications have some limitations in the design of vertical double sheet pile breakwater.Based on the Chinese specification,the calculation result of the active earth pressure behind the wall will deviate greatly from the actual situation if the crest width is smaller,whereas according to the Japanese specification,the calculated resistance moment generated by filling soil behind the wall is inconsistent with the actual situation if the crest width is relatively larger.Thus,it is recommended that for designing the vertical double sheet pile breakwater,both the Chinese and the Japanese methods should be used simultaneously and authenticated mutually,so that a reasonable structure section could be formulated jointly.