Study On The Impact Of A Deep Founfation Excavation On Adjacent Buildings In Changchun City And Prevention And Control Measures

With the strong support of the state for the infrastructure industry,foundation pit projects have been rapidly developed,and deep foundation pit projects are gradually appearing in urban construction clusters.Therefore,ensuring the safety of adjacent buildings during the construction of deep foundation pits is an important issue that needs attention.Based on a deep foundation pit project of a rail transit station in Changchun,this paper summarizes the mechanism of deformation of adjacent buildings caused by deep foundation pit excavation through theoretical analysis,field monitoring data,and numerical simulation.The paper compares and analyses the field monitoring data with the simulation results,derives the influence of deep foundation pit excavation on the surrounding environment and the deformation law of adjacent buildings,and proposes prevention and control measures for the deformation of adjacent buildings caused by deep foundation pit excavation.The paper is presented as follows:(1)By reviewing theoretical articles on the deformation of foundation pits and adjacent buildings caused by deep foundation pit excavation,the paper explains the relationship between the deformation of retaining structures,surface subsidence displacement,and building deformation caused by foundation pit excavation,and clarifies the mechanism of deep foundation pit excavation on adjacent buildings.(2)Based on the actual construction plan and monitoring data of the selected foundation pit section,the paper analyzes the monitoring data of the horizontal displacement of the retaining structure,surface subsidence,and adjacent building subsidence,and summarizes the deformation law with the excavation of the foundation pit.(3)Using the Midas GTS numerical simulation software,the paper simulates the process of foundation pit excavation by setting several working conditions according to the excavation depth,and analyzes the horizontal displacement of the retaining wall,surface subsidence,and building deformation under different excavation conditions,leading to an understanding of the deformation law of adjacent buildings caused by foundation pit excavation.The simulation results are then compared and analyzed with the measured values,and the similarity and reliability of the simulation values and measured values are demonstrated.(4)The paper analyzes the prevention and control measures to reduce building deformation caused by foundation pit excavation.Two methods,including controlling foundation pit deformation itself and reinforcing the soil outside the pit,are discussed.By changing the concrete strength of retaining walls and increasing the stiffness of internal supports,the building deformation can be reduced.After comprehensive consideration of project cost,the paper determines a reasonable and efficient plan to control building deformation.By changing the reinforcement area width,the paper also determines a reasonable reinforcement width under different conditions,providing reference value for future research on similar foundation pit projects.