软黏土地基上沉箱式防波堤在波浪作用下失稳模式分析  

Instability mode analysis of caisson breakwater on soft clay under wave action

作　　者：张华庆[1,2] 尹纪龙[1] 孙熙平[2] 

机构地区：[1]哈尔滨工程大学船舶工程学院,黑龙江哈尔滨150001 [2]交通运输部天津水运工程科学研究所,水工构造物检测、诊断与加固技术交通行业重点实验室,天津300456

出　　处：《水运工程》2015年第5期44-50,共7页Port & Waterway Engineering

基　　金：交通运输部建设科技项目(编号2013328224070)

摘　　要：沉箱式防波堤作为一种典型的防波堤结构形式,以往大多建立在地质条件较好的水域。随着海岸建筑物向离岸、深水和地基软弱地区的发展,恶劣的海洋环境及软弱的地质条件对防波堤设计理论和方法提出了新的、更高的要求。结合实际工程,利用规范方法对沉箱式防波堤稳定性进行了验算并得出最危险工况。通过有限元法研究其失稳机理与破坏模式,分别对无护肩块石、有护肩块石的沉箱式防波堤两种工况进行计算分析,计算结果表明:随着波浪力的增加,软黏土地基尚未形成贯通塑性区发生破坏时,无护肩块石的沉箱式防波堤首先发生滑移失稳破坏;有护肩块石的沉箱式防波堤首先发生倾覆失稳破坏,并且与规范中以后踵为转动点不同,失稳模式为绕沉箱底面以下中轴线偏右某点发生转动失稳。As a typical structure type of breakwaters, caisson breakwaters used to be constructed in the water area with good geologic conditions. With the extending of coastal structures to the offshore, deep-water and soft soil area, harsh ocean environment and soft geologic conditions put forward stronger requirements on the design theory and method of breakwater. Combining with the practical application, we firstly use the code method to compute the breakwater＇s stability and get the most dangerous working condition; and then study the instability mechanism and failure modes by the finite element method under the conditions with and without shoulder stones. The results show that with the increase of wave force, when the cut-through plastic zone of soft clay foundation is formed, the caisson breakwater without shoulder stones slides first; the caisson breakwater with shoulder stone topples first, whose instability occurs in the form of rotation around a point below the bottom surface and on the right of the caisson axis, being different from the point of caisson hind toe in the code.

关 键 词：软黏土地基 沉箱式防波堤 规范法 有限元法 护肩块石 失稳模式 破坏机理 

分 类 号：TU457[建筑科学—岩土工程]