THE DEFORMATION MECHANISM OF A MULTISTORIED BUILDING RAFT FOUNDATION NEAR A DEEP EXCAVATION AND ITS SAFETY CONTROL

摘要

Deep foundation pit excavation has a significant influence on the safety of its adjacent buildings.The deformation characteristics and response pattern change with variety different impact factors,such as geological conditions,pit excavation size and foundation form and so on.Taking the 20m deep station foundation pit and the 13.4m deep passageway excavation as a typical example,this paper thoroughly explores the influence of the two foundation pit excavation on the deformation and settlement characteristics of the raft foundation of the adjacent buildings.Combined with the results obtained by the numerical simulation methods and preliminary information collected from an investigation,it shows that a large lateral displacement occurs at the middle of the segment side wall of the station foundation pit excavation-reduced,which was increased by the excavation of passageway foundation pit.The foundation settlement continuously increased in the excavation,and the differential settlement of the eastern foundation changed significantly in the process of passageway construction.The adjacent buildings slight incline to the direction of the foundation pit.To ensure the project carried out smoothly,the prestress of steel support located at the connection of the station and passageway foundation pit should be appropriate improvement in the construction.