Deep Foundation Pit Deformation Monitoring And Numerical Simulation Analysis For Qingxi Road Station Of Hefei Metro

The safety problem of deep foundation pit is not just reflected in the project itself,but also often has a definite impact on the surrounding environment.In this paper,the deep foundation pit of Qingxi Road subway station in Hefei city is taken as the research background,and the deformation law of the foundation pit,which is excavated with the methods of partitioned and layered excavation,is studied by means of field monitoring and numerical simulation.Based on the comparison of the partitioned and layered excavation and the layered excavation,the difference between these two excavation methods in the stability of the foundation pit is investigated.In addition,by controlling the influence factors of pipeline deformation,the general law of the influence of excavation on adjacent underground pipelines is also studied in this paper.According to the research work,the following conclusions can be drawn.(1)The numerical simulation results are basically coincide with the field monitoring results,and the numerical model can preferably reflect the deformation characteristics of the foundation pit.After the partitioned and layered excavation,the structure of the foundation pit has obvious “bulging belly” deformation,and the settlement curve near the foundation pit presents a groove shape.The deformation law of the two excavation methods is basically consistent,yet the value of overall deformation of the partitioned and layered excavation is less than that of the layered excavation.(2)Under the same condition of excavation and support,the material,diameter and position of the pipeline have great influence on the stress and deformation of the pipeline.With the increase of the stiffness of the pipeline material,the overall deformation of the pipeline is smaller and the stress is greater.The deformation and stress value of pipeline decrease with the increase of pipeline diameter.With the increase of the distance between the pipeline and the foundation pit,the deformation and stress of the pipeline are reduced.The horizontal displacement and stress value of pipeline increases with the increase of buried depth of pipeline.When it reaches the maximum value,it decreases gradually.The vertical displacement of pipeline decreases with the increase of buried depth.