盾构竖井基坑开挖有限元模拟与分析

Analysis on stability of reinforced soil at shield departure area

本文依托穿黄工程北岸竖井超深基坑支护结构的工程实践,利用理论计算和全三维数值模拟计算分析方法,结合实际的监测数据,对深基坑支护结构的受力性能和变形特征进行研究。研究表明,地连墙的受力以压力为主,拉应力和剪应力十分微小,应力水平远低于设计值;对比模拟计算值、理论计算值和实际监测结果发现,虽然三种结果都显示地连墙的径向变形符合一级基坑的要求,但是解析解相对偏于保守,而模拟结果与监测结果相近,但略低于实测值。

Base on the project of foundation pit supporting system of south-to-north water transfer project in yellow,the paper made the analysis on the stress and displacement by means of theoretical arithmetic,numerical simulation and monitoring data.The conclusion is as follow：the stress of the diaphragm wall is given priority to with pressure,tensile stress and shear stress are very small,and stress level is far lower than the design value.And compare the results of theoretical value,simulate value and measured value.The theoretical value is larger than the simulate value and measured value,while the simulation results are similar to the measured value,but slightly lower than the measured values.