摘要
以南京地铁5号线和10号线换乘车站深大基坑开挖工程为背景,对粉土地区基坑开挖时空效应展开研究。结果表明,与一般基坑工程相比,粉土地区深大基坑开挖对周围环境影响明显,表现出显著的时空分布特性:坑外地表沉降随时间表现为多阶段变化规律,在各阶段第二层土方开挖时沉降速率最大,总体沉降为长边沉降大、短边沉降小;受基坑开挖效应影响,地表沉降传递范围远高于2.2H(H为开挖深度);土体深层水平位移沿深度方向表现为类“抛物型”,侧移量表现为西侧变形大、东侧变形小,墙体最大侧移量控制在0.24%H以内;管廊沉降长边方向差异明显,在靠近基坑侧的测线存在显著的沉降差异,该种差异会使结构产生一定大小的剪切力和扭矩,造成结构、防水失效。
Based on the deep and large foundation pit excavation project of Nanjing Metro Line 5 and Line 10 transfer station,the time-space effect of foundation pit excavation in silt area is studied.The results show that compared with the general foundation pit engineering,the excavation of deep and large foundation pit in silt area has obvious influence on the surrounding environment,showing significant spatial and temporal distribution characteristics.The surface settlement outside the pit shows a multi-stage variation law with time.In each stage,the settlement rate is the largest when the second layer is excavated,and the overall settlement is large on the long side and small on the short side.Affected by the excavation effect of foundation pit,the transmission range of surface settlement is much higher than 2.2H(H is the depth of excavation).The deformation of the deep horizontal displacement of the soil along the depth direction is′parabolic′,and the lateral displacement is large on the west side and small on the east side.The maximum lateral displacement of the wall is controlled within 0.24%H;the settlement of the pipe gallery is obviously different in the long side direction.There is a significant settlement difference in the sideline near the side of the foundation pit.This difference will cause the structure to produce a certain amount of shear force and torque,resulting in structural and waterproof failure.
作者
史林肯
SHI Linken(China Railway 14th Bureau Group Co.Ltd.,Jinan Shandong 250014,China)
出处
《铁道建筑技术》
2024年第4期55-61,共7页
Railway Construction Technology
基金
中国铁建股份有限公司科技研发计划项目(2020-B05)
国家重点研发计划项目(2023YFC3806700)。
关键词
深大基坑
土体变形
时空效应
管廊沉降
现场监测
deep and large foundation pit
soil deformation
space-time effect
pipe gallery settlement
on-site monitoring
