应力主轴旋转对波浪作用下堤防变形的影响分析  

EFFECTS OF PRINCIPAL-STRESS-AXIS ROTATION ON THE DEFORMATION OF A DAM UNDER WAVE LOADING

作　　者：童朝霞[1,2] 张建民[2] 张嘎[2] 

机构地区：[1]北京航空航天大学交通科学与工程学院,北京100191 [2]清华大学水沙科学与水利水电工程国家重点实验室,北京100084

出　　处：《工程力学》2009年第10期67-73,共7页Engineering Mechanics

基　　金：973项目课题(2007CB714108);国家自然科学基金项目(50679034)

摘　　要：波浪荷载作用下堤防中将发生明显的应力主轴旋转。该文基于考虑应力主轴循环旋转效应的砂土弹塑性本构模型,实现了该本构模型的数值算法并嵌入到大型通用有限元计算程序MSC.Marc。对某概化堤防在波浪荷载作用下的变形进行的有限元分析结果表明:在波浪荷载作用下,向波浪荷载作用一侧的水平方向变形和向地基底面沉降的竖向位移是堤防的主要变形趋势;同时相比不考虑应力主轴旋转,考虑应力主轴旋转将对堤防的变形产生以下影响:1)增大水平位移和竖向位移的最大值;2)扩大变形的区域;3)影响变形的分布。在工程中若不考虑实际发生的应力主轴旋转将导致偏于危险的设计。The principal stress axis rotation was occurred widely for dams under wave loading. Based on the elasto-plastic constitutive model of sands considering the effects of a cyclic rotation of principal stress axes, the pragmatic stress integration algorithm of the model was developed and incorporated into the FEM software of MSC. Marc, used to analyze the deformation of a typical dam under wave loading. Results show that the deformation tendency of the dam in the horizontal direction is along the side of wave loading application and that in the vertical is the settlement to the bottom. Meanwhile it is found that the deformation of the dam is influenced greatly if the effects of principal stress axis rotation are considered. Compared with the deformation of the dam with and without effects of principal stress axis rotation, the effects of principal stress axis rotation will occur in the following aspects： 1） increasing the maximal horizontal and vertical deformation; 2） enlarging the deformation area; 3） affecting the distribution of the deformation. The dangerous design may be induced if the effects of principal stress axis rotation are not considered in the real projects.

关 键 词：应力主轴旋转 波浪荷载 堤防变形 有限元分析 本构模型 

分 类 号：TU435[建筑科学—岩土工程]