佛山地铁二号线湾华站深基坑开挖的变形特性分析

Analysis of Deformation Behavior during Excavation of Wanhua Station of Metro Line 2 in Foshan

地铁的修建尤其是车站的施工和盾构的始发过站等都涉及深基坑的开挖,需要通过监测关注开挖过程中的基坑变形.以佛山地铁二号线湾华站深基坑为工程实例,对围护结构和坑外地表的监测数据进行了整理分析.结果表明,围护桩在开挖过程中表现出内凸型的变形模式,最大水平位移发生在0. 7倍至0. 8倍开挖深度处.坑外地表沉降呈现出凹槽形,最大地表沉降发生在距坑边3 m处.根据实测和理论分析,该基坑开挖的影响范围为2倍开挖深度.

Monitoring of foundation pits in the process of excavation is essential for metro building, particularly for station construction and shield departure of a subway project. Taking Wanhua Station＇ s deep foundation pit of Metro Line 2 of Foshan City as a case study, this paper studies the monitoring data of retaining structure and ground. The results show that the retaining pile is deformed in the form of interior convex in the process, and that the maximum horizontal displacement of retaining structure occurs at 0.7 to 0.8 times of the excavation depth; the mode of ground settlement is groove, and the maximum settlement occurs 3m away from retaining structure. Based on the monitored data and theoretical analysis, the influence range of the pit excavation is twice as long as that of excavation depth.