Study On Endogen Force And Deformation Of Foundation Pit Under Asymmetric Overload

Under the action of asymmetric overload,the soil pressure on piles (wall) and the axial force of support structure changes due to the interaction of the foundation pit support structure leading the internal force,deformation of the overall building envelope have obviously changed different from the situation of symmetry overload.This paper,referencing the foundation beam model of Winkler and some of the assumptions of co-deformation theory, using independent of each other linear spring to simulate the soil of both sides,assuming that relaxation stress and compression stress have a linear relationship with the displacement of piles (wall),establishes the plane frame computing model,and in this model the impact of excavation on both sides of each is considered.This paper researches the standard mileage section DK17+190~DK17+290 portion of Meilan Airport Tunnel which is in Haikou city,Hainan Province,uses finite element to analyse the department of the entire construction process including excavation,steel shotcrete making, and applying prestress.At the same time, it summarizes the difference of the internal force,deformation of the overall building envelope from the situation of symmetry overload and discusses the factors which impact the internal force and deformation of foundation pit.Through the lateral deformation of the pile and the axial force of steel shotcrete which is monitored at foundation pit,the study acquires the time-axis force curve of the lateral deformation an the axial force of steel shotcrete,and masters the change of the deformation and internal force of support structure.Meanwhile it summarizes the rule of internal forces and deformation in foundation pit construction process under asymmetric overload,and compares with the numerical simulation results,discusses and summarizes the measures of controling the deformation of building envelope.