某城市地铁车站基坑地表沉降变形研究

通过对北方某城市地铁1号线一期工程地铁深基坑地表沉降监测数据进行统计分析,讨论地表沉降与基坑支护类型、开挖深度的关系。结果表明:地铁车站基坑开挖引起的地表变形最终表现为"凹槽形";地铁车站基坑地表最大沉降变形量为0.01%H～0.05%H,平均值为0.03%H;地铁车站基坑开挖引起的地表沉降值大多位于0～5 mm,小于控制值;在其他条件(基坑长度、宽度、周边环境)大致相同的前提下,地表沉降值随开挖深度的增大而增大,随支撑刚度的加大而减小。

Research on Ground Surface Settlement Deformation at a Foundation Pit of Urban Subway Station

For the deep foundation pit in Phase I of the metro line 1 of a city in the north, the monitoring data of the ground surface settlement was input to statistical analysis so as to discuss how the ground settlement related to the foundation pit supporting and the excavation depth. The result shows that, the ground surface deformation caused by deep excavation at the subway station presents concave groove shape finally; the maximum subsidence deformation thereof is 0.01 %H ~ 0.05 %H, and the average value is 0.03 %H; the subsidence caused by the excavation of foundation pit is 0~5 mm mostly and less than the control value; providing the conditions (length and width of the foundation pit and the surrounding environment) are approximately the same, the subsidence of ground surface increases with the increasing excavation depth and decreases with the increasing support stiffness.