Research On Design And Numerical Simulation Of Soil Nail Wall&Pile Anchor Support In Deep Foundation Pit

As the increasing of deep foundation pit project, the problems existing in the design and construction of deep foundation pit supporting outstanding year by year, especially how to reduce costs under the premise that ensure the safety of foundation pit and its surrounding environment has become a key problem need to solve currently.This paper is based on deep foundation pit supporting engineering of fengtai sea door tuen business financial project, through studying the theory of the deep foundation pit supporting, Lizheng geotechnical design software is used for soil nail wall and pile anchor combined support structure design and stability checking. Combining with FLAC3D numerical simulation software to simulate the process of deep foundation pit excavation, at the same time, compare the design and the simulation results with the actual monitoring data in the process of the deep foundation pit excavation. And study the soil nailing wall and pile anchor combined support structure of the stability and deformation law. Get the following results:(1) Summarized the existing research results at home and abroad, through summarizing and concluding current situation of the deep foundation pit engineering support related theory, concluded the right scope and conditions which are suitable to the different kinds of the deep foundation pit supporting.(2) Through the analysis of the characteristics of deep excavation, the engineering geological conditions and the surrounding environment, scheme comparison and selection of soil nails and anchor pile support design scheme, and using Lizheng geotechnical software for the design of deep foundation pit support scheme and stability calculation. Through analyzing the calculation results, the design was verified to be economy and rationality.(3) Using the numerical simulation software FLAC3D to simulate various working conditions in the process of deep excavation, and get the internal force and displacement of retaining structure, sedimentation and other parameters. Through analyzing the simulation results, found out as the deep foundation pit excavation, how supporting structure and surrounding soil horizontal displacement and settlement of foundation pit deformation and internal stress of soil changes.(4) Compared the calculation results of Lizheng design software with numerical analysis software and actual monitoring about subsidence and horizontal displacement value of pile body, the results show that the results of numerical analysis and the calculation results of Lizheng design software and actual value are basically identical. The results show that the soil nail wall and pile anchor combined support structure design is reasonable and economic.