Research on Land Subsidence Caused by Foundation Pit's Dewatering

摘要

The prediction of land subsidence in the vicinity of deep foundation pit during the course of dewatering and excavation is a significant criterion for the designation of deep foundation pit.Based on FLAC3D numerical model calibration and identification of foundation pit dewatering and excavation in Tianjin area,this paper analyze the relationship between maximal subsidence,maximal range of influence and some parameters.The results shows that the contour of land subsidence near foundation pit occurs radically and the major of subsidence is concentrated on places within the scope of distance from center of foundation pit whose value is two times depth of excavation,as well as the maximal subsidence is about 5 m away from foundation pit.Furthermore,when single parameter such as hydraulic conductivity or depth of dewatering increase,the maximal subsidence and range of influence increase with them.On the contrary,when single parameters such as modulus or depth of impermeable wall increase,the maximal subsidence and range of influence decrease with them.