Construction Monitoring And Numerical Simulation Of Pile Anchor Support Structure For Deep Foundation Pit In Changchun

With the accelerated pace of urban construction,the demand for land is increasing day by day.In order to save land,people begin to develop and use underground space,and then a large number of foundation pit projects appear.Today,because of the design and construction of foundation pit engineering does not meet the stipulate and other factors which has lead the collapse occurred,the accident will not only affect the construction period,but also increase the cost of the project.Therefore,it is necessary to carry on the in-situ monitoring and numerical simulation analysis of the foundation pit engineering,to guide the construction scientifically and reasonably,and to ensure the secure and stability of the foundation pit engineering.The article is based on the deep foundation pit engineering of Changchun Haihang International Square second-phase project,adopt the methods which the theoretical analysis,field measurement and numerical simulation using FLAC^3D software are combined.The text discusses the change regulation,deformation of support structure,internal force and the sedimentation of the surrounding ground during the excavation and support process of the deep foundation pit,which under the pit support of pile anchor.And the results obtained can provide some reference for the design and construction of similar projects in this region.The main research contents of this thesis are as below:?1?The paper summarizes the types of foundation pit support and the deformation mechanism of foundation pit excavation,and the structure,working principle,failure mode and mechanical analysis of the pile anchor supporting structure are studied.?2?Depended on the deep foundation pit engineering of Changchun Haihang International Square second-phase project,according to the specification and design requirements to determine the monitoring scheme of the deep foundation pit,based on the data collection of autual measurement,obtain the deformation law that pile anchor retaining structure deformation,internal force and surrounding ground deformation when excavate and support the foundation pit,according to the deformation law the safety state of the foundation pit is mastered so as to ensure the smooth progress of the construction.?3?Using FLAC^3D numerical simulation software to set up the three dimensional foundation pit model,and then to simulate and calculate the whole process of foundation pit excavation and support,get the deformation law under different conditions of soil horizontal displacement,vertical displacement and internal force of the structure,and the measured results are compared with the simulation results to verify the reliability of the numerical simulation.?4?Based on the numerical calculation,to study the influence of the depth of pile,ground load and soil parameters and the cable angle on the deformation of foundation pit.The results obtained can provide some theoretical guidance for the design and construction of similar projects in this region.