Numerical simulation based on the three dimensional full coupling model between deep foundation pit dewatering and land-subsidence

To calculate the land subsidence caused by deep foundation pits dewatering in quaternary loose sediment layer,a mathematics model based on Biot's consolidation theory was built.Then Biot's consolidation theory was extended and applied to non-linear question.A 3D coupling-model of seepage and stress was established with considering the dynamic change of permeability coefficient by the different stress state.The three dimension finite element analysis method was used in Shanghai Huanqiu Finance Center foundation pit dewatering,to simulate and analyze the character of groundwater level and land subsidence distortion around the foundation pit by dewatering in detail,accordingly the groundwater level and the land subsidence distortion quantity around the foundation pit are achieved as the water table of the foundation pit center reduces to-22m,which was proved to be correct and reliable by follow-up project.The model has important significance in project practice.