Study On Stability Of Foundation Pit And Mechanical Effect Of Excavation In Saturated Soft Soil

This paper takes Shanghai Expo underground substation engineering of foundation pit supporting structure stability as the research object,according to The stability of foundation pit support structure is studied,and The field monitoring results are analyzed.Analysis of the Expo underground substation of foundation pit support structure and the main engineering supporting structure selection basis for foundation pit excavation area influence scope mechanical effect of in-depth study of the system.This chapter will use the finite element numerical simulation method,the problem of mutual influence different spacing and different excavation depth of foundation pit excavation for the adjacent partition,design of foundation excavation in soft soil area And provide some reference and technical support for follow-up construction.The main research work are as follows:(1)structural stability design and field monitoring analysis of underground substation foundation pit of Shanghai ExpoThe internal force and deformation of retaining structure of typical foundation pit in Shanghai area are mainly analyzed.Mainly includes the foundation pit stability checking;overturning stability checking of foundation pit excavation;overall stability;stress and deformation analysis and reinforcement calculation as well as the support system,design method of checking the stability of foundation pit excavation engineering provides technical specification for reference,through the analysis of monitoring results in foundation pit construction,verification period the overall stability and operation of the foundation pit safety.(2)foundation pit project of Shanghai Expo underground substation stability finite element analysisBy constructing a two-dimensional elastic-plastic finite element model for stability analysis of foundation pit project of Shanghai Expo underground substation,the main consideration step by step,partition of excavation in the actual construction process,and the supporting structure stress and deformation,ground settlement and layered settlement,and the excavation process of pore water pressure distribution system analysis,in order to to provide theoretical guidance and forecast for construction site.(3)Analysis of interaction between excavation and sub excavationThe method of finite element numerical simulation on the part of the foundation pit,according to the different spacing and different excavation depth of foundation pit adjacent partition interaction of this problem,and discusses the influencing factors of foundation pit excavation partition mechanical effect,vertical and horizontal displacement of soil underground continuous wall after a comprehensive analysis of the results can to better guide engineering practice.