Study On The Safety And Deformation Control Of Adjacent Existing Frame Buildings By Foundation Pit Excavation

Foundation pit excavation causes deformation of surrounding soil,uneven settlement of adjacent existing frame building foundation,and damage to the whole structure easily,which affects the safe use of the building.The foundation pit engineering environment of urban subway station is complex,there are many structures nearby,and there are many safety risks.By analyzing the structural safety and related influencing factors,predicting the possible adverse effects and taking measures in advance,we can avoid some unnecessary losses.This paper combines a subway station pit project in Zhengzhou to study the impact of pit excavation on adjacent existing frame buildings and analyze the interaction law between pit excavation and building foundation,the main research content is as follows:(1)Establish a numerical model to analyze the influence law of foundation excavation on the deformation of soil and enclosure structure on the side with and without building,combine the measured data of the project,and compare the numerical results with the measured results to verify the reasonableness of the model.(2)Based on the theory of damage to buildings adjacent to foundation pits under the joint action of tensile strain and angular deformation,the damage levels of existing frame buildings adjacent to foundation pits were evaluated by building damage assessment guidelines based on the numerical results of vertical and lateral deformation at the corner locations of each wall of the building.(3)Analyze the influence law of building parameters and foundation support parameters on the foundation deformation of frame buildings by numerical method,and establish the linear function relationship between the relative bending stiffness and relative axial stiffness of buildings with different heights and widths and the maximum value of foundation settlement based on the condition that the foundation pit is at the same distance from the building.(4)Study the influence of the depth and stiffness of the pit bottom plus solid on the deformation of building foundation,combine the factors of building parameters and pit support parameters that affect the deformation of building foundation,optimize the construction plan and reduce the influence of pit excavation on building deformation.