坑中坑基坑应力场的参数化分析

Parametric analysis on stress field of pit in pit excavation

基坑工程中的坑中坑问题是一个非常普遍但又没有进行深入研究的问题。以坑中坑为研究对象,将其分为内坑与外坑,按内、外坑的相对位置关系将各区域进行了划分。提出了表现坑中坑特点的4个参数,即:内、外坑面积比m、内、外坑深度比h、坑趾系数U、内坑挡墙插入比α。采用有限元软件ANSYS建立典型坑中坑数值模型,详细分析了坑中坑各参数m、h、U、α变化对大基坑应力场的影响,从中得出了影响最大的参数,坑中坑最敏感的应力区等有益结论。

Problem of 'pit in pit'(PIP) is a universal problem which hasn’t been researched deeply.The research object of this article is PIP in deep excavation.According to the relative position of inside pit and outside,the whole pit is divided into several regions.The feature of PIP is characterized by four parameters,namely:the area ratio of inside and outside(m),the depth ratio of inside and outside(h),pit toe coefficient of U,the wall insertion ratio of the inside pit(α).Finite element analysis of the model is carried by ANSYS,and the influence of the parameters m,h,U,α on stress field of the large excavation is studied respectively.Some useful conclusions,such as:the foremost parameter and the most sensitive stress field in pit in pit achieve.