Numerical Simulation And Reliability Research On Excavation And Supporting Of Deep Foundation Pit

Besides strength and stability, deformation must be controlled to meet the demand onsupporting structure of deep foundation pit. In area of soft soil the deformation control ismore significant to the excavation and supporting of deep foundation pit and the research on itis very important significance.In this paper figures on in-situ monitor are gleaned from a large project, Yujiapu Stationdeep foundation pit project, which located in Binhai New Area of Tianjin. Analyses isconducted on the in-situ monitor data. The study focus on the deformation regularities of theretaining wall and stress change of supporting elements and several useful conclusions aredrawn. Simulation on the construction process of retaining and excavation is also completed,in which FLAC3D software is chosen. By comparing the results of simulation and in-situmonitor, it is found that the trend is accordance with each other though slight difference existsin numerical values. This indicates that calculation model in simulation is correct andparameters selection and calculation method are reasonable.Limit states functions on three different supporting types: cantilever type, single fulcrumsupporting type and multiple fulcrum supporting type are deduced, in which the index ishorizontal lateral displacement of retaining wall. A computer program in Matlab languagebased on Monte Carlo method for reliability analysis is completed to judge the reliability ofsupporting wall of deep foundation pit and evaluate the safety of pit, in which the parameter isthe horizontal lateral displacement.Different method including theoretical analysis, in-situ monitoring, numerical simulationand reliability analysis are used to study the deformation regularities of the retaining wall andstress change of supporting elements. The achievements of the work can be reference to thedesign and construction of similar project.