含损伤岩体的深基坑开挖对邻近桥梁桩基变形与受力的影响OA

Urban subway tunnel construction frequently requires traversing complicated ge-ological environments and nearby structures.The excavation of deep foundation pits invol-ving underlying damaged rock masses is prone to inducing deformation in adjacent bridge pile foundations,thereby threatening engineering safety.To address the deficiencies in ex-isting research regarding dynamic unloading damage mechanisms and the interaction be-tween rock-soil masses and pile foundations,a quantitative relationship between the geo-logical strength index(GSI)and the damage variable is established.Based on a subway foundation pit engineering case in Guangzhou,a coupled numerical model encompassing the damaged rock mass,foundation pit,and pile foundation is developed using FLAC3D to analyze the impact of foundation pit excavation on the deformation behavior of adjacent bridge pile foundations.The results demonstrate that:1)it is feasible to employ damage mechanics parameters for the numerical simulation of the impact of deep foundation pit exca-vation with underlying damaged rock masses on adjacent bridge pile foundations;2)the re-taining structure and the properties of the rock and soil masses exert a significant influence on stability during foundation pit excavation;and 3)the rock mass damage effect amplifies the horizontal displacement of the pile foundations,which exhibits a non-linear growth trend as the excavation depth increases.These research findings can provide a theoretical basis for risk control in engineering projects situated within sensitive urban environments.