基于PLAXIS的基坑开挖模拟研究

文中以实际工程为背景,利用Plaxis模拟了隧道某一断面在静水压力作用下的基坑开挖过程,模拟结果表明当基坑开挖到基底时,地连墙最大位移及所受弯矩的最大值均位于其中间位置,剪力最大值位于上部1/4位置处;基坑开挖将会产生应力重分布,主应力的方向表明开挖底部存在一个较大的被动土压力区和横向支撑后面的一个小的被动土压力区,在静水压力的作用下基坑开挖还会引起基底隆起,且基底隆起的位移量较大。

SIMULATION OF FOUNDATION PIT EXCAVATION BASED ON PLAXIS

Based on practical engineering background, the finite element analysis software Plaxis is used to simulate a deep foundation pit excavation process of a tunnel section under hydrostatic pressure. Simulation results show that the maximum horizontal displacement and bending moment of the diaphragm wall will appear at the middle position of the wall and the maximum shear force is located at the upper 1/4 position when foundation pit is excavated to the bottom. The excavation of the foundation will cause a stress redistribution, and the direction of the principal stress indicates a large passive earth pressure area at the bottom of the excavation and a small passive earth pressure zone behind the lateral support. The uplift of pit bottom will be induced by the excavation under the hydrostatic pressure and the displacement is large as well.