Simulation Analysis And Engineering Monitoring Of Deep Foundation Pit Excavation In Subway Station

In order to solve the urban traffic problem,many big cities began to build subway.With the rapid development of urban subway construction,there are more and more deep foundation pits in metro stations,they have the characteristics of complex surrounding environment,deep excavation and high construction risk.To ensure the construction safety of deep foundation pit in subway station,reasonable design,excavation simulation and engineering monitoring are very important.For this reason,this paper takes the deep foundation pit of a subway station in xi 'an as the engineering background,the numerical simulation,design optimization and engineering monitoring of deep foundation pit excavation in metro station are carried out.First of all,this paper introduces the geological conditions and surrounding environment of deep foundation pit engineering of a subway station in xi 'an,on the basis of analyzing the commonly used enclosure structure of deep foundation pit in the domestic subway station,it is confirmed that the deep foundation pit of this station is constructed by bored cast-in-place pile,the preliminary design scheme of the enclosure structure is proposed;Then,the soil pressure is calculated according to the layered soil,and then the calculation of the internal force of the structure.Then,using GEO5 geotechnical engineering software,the three design schemes of deep foundation pit in this station are analyzed numerically,the displacement,the shear force and the bending moment value are obtained,through the comparison and analysis of the calculation results,on the basis of considering the internal support position and soil depth on the foundation pit,the optimization scheme of the foundation pit enclosure structure is obtained.Through the simulation calculation of the excavation of the deep foundation pit,the internal forces and displacements of the surrounding structures under various excavation conditions are obtained,the results show that the design parameters of the envelope can satisfy the safety construction requirements of the deep foundation pit of the station;Finally,in the excavation process of deep foundation pit,the construction technology of subsection is adopted,and the information construction monitoring is carried out,a lot of measured data is obtained,which effectively guides the construction and ensures the excavation safety of the foundation pit.In addition,the simulation results are consistent with the field monitoring data,it can provide reference for the design and construction of deep foundation pit in subway station under the same condition.