深基坑多层水平支撑温度应力的简化计算方法

A Simplified Method of Calculating Thermal Stress For Multilayered Horizontal Struts In Deep Excavations

摘要:

假设墙后土体服从Winkler地基模型,地下连续墙变形采用一端固定、多点支承的矩形板模型,同时假定温度变化引起围护体变形较小并在竖向呈线性分布,在考虑支撑—连续墙—土协调变形的基础上,建立了深基坑中多层水平支撑温度应力的一个简化计算方法.编制了计算程序,探讨了连续墙厚度对支撑温度应力的影响,并将计算结果与实测数据进行了对比,结果表明:墙体厚度越厚,支撑温度应力越大,温度变化对支撑轴力具有较显著的影响.

关键词:深基坑; 多层水平支撑; 连续墙; Winkler地基;温度应力

Abstract:

The Winkler foundation model is used to simulate the behaviour of the soils behind the diaphragm,the deflection of the diaphragm can be obtained using the rectangular plate model with one edge builtin and multicornered point supported,based on the interaction and the deformation compatibility between the struts,the diaphragm and the soils,a simplified method of calculating thermal stress for multilayered horizontal struts in deep excavations is deduced by considering temperature fluctuations vary linearly along the vertical direction.Numerical analysis is carried out by using the corresponding program based on the theory.The influence of diaphragm stiffness on thermal stress of horizontal struts is discussed,and the computational results are compared to that of the measured data with a good precision.Numerical results show that the thicker of the diaphragm is,the bigger the thermal stress of horizontal struts is,and temperature fluctuations have a remarkable effect on the stress state of multilayered horizontal struts in deep excavations.

Key words:deep excavation; multilayered horizontal struts; diaphragm; Winkler foundation; thermal stress.