天津软土高铁深基坑地下连续墙尺寸对水平侧移量及地表沉降量的影响  

Influence of Diaphragm Wall Size on Lateral Displacement and Surface Settlement of Foundation Pit of Soft Soil High-speed Railway in Tianjin

作　　者：孙根强 Sun Genqiang(Xiongan High Speed Railway Co.,Ltd.,Shijiazhuang 071700,China)

机构地区：[1]雄安高速铁路有限公司,河北石家庄071700

出　　处：《市政技术》2024年第12期206-213,222,共9页Journal of Municipal Technology

摘　　要：以天津软土地区津潍高铁明挖段某深基坑工程为研究背景,采用PLAXIS 2D数值模拟软件构建了数值计算模型,并结合现场监测方案获取实际数据开展了对比研究,分析了不同地下连续墙厚度与深度对其水平侧移量及基坑周边地表沉降量的影响规律。研究结果表明,数值模拟结果与实际监测结果高度吻合,验证了数值模型的可靠性。进一步分析发现,地下连续墙厚度是控制变形的关键因素,增加墙体厚度能够显著减小侧移和沉降。此外,数值模拟结果和实际监测结果均显,地下连续墙的水平侧移量在15~25 m深度范围内达到最大值,且基坑周边的地表沉降量在距地下连续墙约10 m处最为显著,形成典型的“对勾”形沉降曲线。基于上述研究结果,提出了优化地下连续墙厚度与深度的建议,为有效控制软土地区高铁深基坑变形提供参考。A foundation pit excavation project of the Jin-Wei high-speed railway in soft soil of Tianjin is taken as an example.A numerical calculation model is established by PLAXIS 2D software.Combined with the field monitoring scheme,the actual data was comparative studied.The impact of various depths and thicknesses of the underground diaphragm wall on its lateral displacement and the surface settlement amount was analyzed.The results indicate that the numerical simulations and field monitoring are highly compatible,which verified the reliability of the numerical model.Further analysis reveals that the thickness of the underground diaphragm wall is a crucial factor in controlling deformation,the increased thickness significantly reduces lateral displacement and settlement.Both numerical simulations and measured data show that the maximum horizontal displacement of the wall occurs within a depth range of approximately 15~25 m,the most significant surface settlement occurring at a distance of approximately 10 m from the wall,and forms a typical“tick-mark”settlement curves.Based on these findings,recommendations are made to optimize the depth and thickness of the diaphragm wall in order to more effectively control deformation in deep excavations for high-speed railways in soft soil regions.

关 键 词：深基坑 支护结构 水平侧移量 地表沉降量 PLAXIS 施工监测 

分 类 号：TU93[建筑科学—结构工程]