Study On Influence Of Foundation Pit Excavation On Bearing Capacity Of Natural Foundation

With the rapid development of the city,the development and utilization of underground space has become a trend.Therefore,the foundation pit project has become one of the research hotspots in the field of civil engineering.The excavation of foundation pits will,on the one hand,affect the foundation bearing capacity of adjacent buildings(structures)on the outside of the foundation pit,and on the other hand will also affect the bearing capacity of the natural foundation in the foundation pit.This paper use PLAXIS 3D finite element software to simulate the impact of earth excavation of foundation pit on the bearing capacity of the foundation in different positions in the pit.Analyze the influence of the position of the external load of the pit,the form of support and the width of the foundation pit on the bearing capacity of the foundation in the pit.The main research contents of the paper are as follows:1.Using PLAXIS 3D finite element analysis software,a 3D finite element model for a foundation pit project is established.Analyze the ground settlement outside the pit,the lateral deformation of the support structure,the vertical deformation of the support structure,and the uplift of the bottom of the pit in the excavation conditions of the foundation pit.Comparing the numerical simulation data with the monitoring data,the two datas are consistent,verifying the reliability and rationality of the finite element model and parameter selection.2.When the soil is medium coarse sand and silty clay,respectively,a homogeneous soil foundation pit model is established to analyze the change in bearing capacity of soil foundations at different positions in the bottom pit of the foundation pit,and the impact of external load of the pit on the bearing capacity of the foundation is considered.3.The homogeneous sand soil foundation pit is the research object.In-depth analysis of the position of the overload outside the pit,the form of support,and the change in the width and depth of the pit,the foundation at the bottom of the pit in the pit change in bearing capacity.