软土基坑SMW工法墙墙顶位移与嵌固比关系模拟试验研究

Simulation Test Study on the Relation of the Displacement on the Top of SMW With the Embedded-ratio

基于相似理论设计了SMW工法支护的软土深基坑支护开挖试验模型,由模型试验测得了各级开挖稳定后的SMW工法墙墙顶位移;在模型试验基础上,采用大型非线性有限元软件ABAQUS建立了特征墙段的三维有限元数值分析模型,由数值分析也获得了各级开挖工况下墙顶位移.比较了基坑模型试验及其数值模拟分析结果,并采用指数模型拟合了SMW工法墙墙顶位移与嵌固比关系曲线.结果表明:采用指数模型拟合SMW工法墙墙顶位移与嵌固比关系可取得良好的拟合效果.工程施工中,可采用指数模型预测预报SMW工法墙随基坑开挖产生的墙顶水平位移.施工过程中,加强墙顶位移监测,绘制墙顶位移与嵌固比关系曲线,将预测位移值与实测值进行分析对比,可以了解支护结构实际所处的工作状态及变形阶段,从而可以预防工程事故发生.

Based on the theory of Similarity, the model of trial pit supported by SMW and the displacement-values on the top of wall after excavation were measured. Based on the model test, three-dimensional finite element analysis model of characteristic-wall was made by the large-scale non-linear finite element software ABAQUS and the displacements on the top of SMW at each excavation-step was obtained. The results of the pit model test and nu- merical simulation analysis were compared and the relation curve of the displacement with embedded-ratio was fitted by means of the model of exponential function. It was shown thatgood fitting effect could be obtained when the relation curve of the displacement with embed- ded-ratio was fitted by means of the model of exponential function. In engineering construc- tion, the displacement-values on the top of wall as the excavation could be forecasted by the model of exponential function. To prevent the engineering accidents happen, the displace- ment-values on the top of wall should be monitored and the relation curve of the displace- ment with embedded-ratio should be drawn. By analysing and comparing the measured-val- ues with its forecast-values, one can find out the actual working state of the supporting sys- tem and assess its stage of deformation and thereby prevent the happening of accident.