The 3D Finite Element Numerical Simulation And Analysis Of The Foundation Pit Considering The Effect Of Seepage

Groundwater-lowering is a difficult problem of the foundation pit engineering,and most accidents of foundation pit engineering are related to groundwater seepage,so doing research and analysis on groundwater is very important. The groundwaterseepage may cause foundation pit destabilization, drift sand, piping effect, landsubsidence, and what is more it has impacts on building, underground pipe and otherpublic facilities around the pit. Therefore, the control of groundwater and reduction ofits negative influence upon foundation pit and surrounding environment become veryimportant in deep excavation project.For researching seepage fields, the foundation pit excavation is simulated byusing the finite element analysis program in the paper. Above all, the choice of soilconstructive model may directly impact the calculation result's accuracy. This paperintroduces an advanced soil constructive model Hardening-Soil model, which is goodat dealing with loading-unloading problem, and analyses the impacts on result whenchanging its parameters. In contrast to Mohr-Coulomb model, we can proveHardening-Soil model's superiority.On the basis of 2D finite element analyses of seepage fields in foundation pits,this paper considers spatial effects, simulates the foundation pit excavation with 3Dfinite element and compares its result with 2D's. 3D simulation can give the impactscaused by the space layout of foundation pit, the anisotropy of permeabilitycoefficient and the division of layer, thus the deficiency of 2D may be diminished, wecan get more practical results. The deformation of support structure and heave of thebottom of the foundation pit which are gotten by 2D's analysis are both larger than3D's. But in actual engineering while simulating the excavation of the foundation pitwe usually consider it as plane problem. So we can get more visualized results.Although the result of 2D is a little conservative, it has advantage and practicability.So combining the analysis of 3D and 2D in actual situation will provide moreacademic basis on design and construction of foundation pits.