Study On The Application Of Super-long Steel Tube Static Pressure Pile In Strengthening Existing Buildings

With the increase of the density of buildings in soft soil area,foundation pit engineering is often in dense buildings nearby.The additional deformation caused by deep foundation pit construction and its influence on the surrounding buildings make the foundation pit construction more difficult.The reinforcement of existing buildings is significance to the construction of deep foundation pit in soft soil area.According to the reinforcement project of Ning Gong Xin Yu 4,8,11 buildings in Nanjing,this paper focouses on super-long steel tube static pressure pile in reinforcing existing buildings through the ways of theory analysis,numerical simulation and field test methods.Firstly,this paper summarizes the working principle of anchor pile technology.The foundation pit excavation causes stress redistribution of soil around the foundation pit.Analyze the impact of buildings deformation according to soil deformation,additional load,buried depth.On this basis,the paper discusses the influence of different positions and different foundation forms on the deformation of the strata.Secondly,this paper uses FLAC 3D numerical simulation software to establish a numerical model in the original building foundation and super-long steel tube pile.And observe differences under various construction conditions of foundation pit and its impact on the surrounding environment,especially the settlement of Ning Gong Xin Yu buildings.Then make the following analysis:a comparation of the houses in different conditions,the influence degree of foundation pit construction adjacent buildings;by comparing the differences of the pit itself(the deformation of the retaining structure)and the surrounding environment influence(surface subsidence and heave)analysis of the influence of super-long steel tube pile and the foundation pit;super-long steel tube pile horizontal deformation observation of foundation pit construction.The super-long steel tube pile using to resisting soil horizontal displacement is very effective.Finally,according to Ning Gong Xin Yu 4,8,11 buildings reinforcement engineering design scheme and the piles data statistics,this paper analyzes super-long steel tube pile in the soft soil area calculation method and plugging effect calculation method.With the foundation pit field building settlement data,analyzes the influence of foundation pit excavation on surrounding buildings.Compare between different stages of construction,settlement of buildings before and after the reinforcement of buildings.And the numerical simulation results verify the above check.Super-long steel tube static pressure pile in soft soil area to improve the building deformation resistance is very efficient.