Numerical Simulation Analysis And Optimization Of A Deep Foundation Pit With Pile Anchor Supporting Structure

At present,there are more and more high-rise and super high-rise buildings in our country,and the depth of foundation pit is also deeper and deeper.In order to ensure the safety of construction personnel in the process of foundation pit excavation and reduce the occurrence of engineering accidents,the design and deformation control of foundation pit supporting structure are also higher and higher,so it is necessary to study and optimize the deformation characteristics of supporting structure.Based on the deep foundation pit project of a high-rise residential community in Handan,Hebei Province,combined with the project site investigation report,this thesis analyzes the soil layer information,refers to the relevant codes and regulations,and finally selects the form of pile anchor support after various comparisons.Combined with Lizheng deep foundation pit design software,the supporting structure of unit 1-1 in the west of the foundation pit is designed and checked,the deformation of the supporting structure under the elastic fulcrum method is obtained,the field monitoring data are sorted out,and the deformation law is found.FLAC3D software is used for modeling and finite element simulation to analyze the soil displacement,surrounding soil settlement,support pile displacement and Anchor Cable axial force during foundation pit excavation.It is found that the horizontal displacement of the support pile increases with the excavation,reaching the maximum value of 13.36 mm near half of the excavation depth.The surrounding soil settlement increases with the excavation,and the influence distance gradually becomes farther,the farthest is 9m.The maximum settlement is 8.39 mm near 3M outside the pit wall.By comparing the design value,simulation value and monitoring value,it is found that the deformation law of foundation pit is consistent and less than the design value,which meets the specification requirements and reflects the correctness of this numerical simulation.Based on the original design scheme,the influence of changing pile diameter,pile length,pile spacing,anchor cable prestress and anchor cable inclination on the deformation of support structure is studied by controlling variable method.16 groups of parameters are selected for optimization by orthogonal test method,and the final optimization scheme is obtained and verified.The new scheme reduces the deformation on the basis of ensuring economy,Make the support structure more safe and reliable,so as to achieve the purpose of optimization.