超大埋深基坑降水开挖结构安全性分析及对地表沉降影响

Analysis on the Structure Safety of Dewatering and Excavation of the Foundation Pit with Super-large Buried Depth and Its Influence on the Surface Settlement

依托广西南宁轨道3号线埋深超过60 m的青秀山明暗挖地铁车站工程,进行了降水对地表沉降影响以及基坑开挖对围护结构安全性分析。结果表明:随着降水深度的增加,地表沉降增大,与基坑距离越近,地表沉降量越大;深基坑采用分层开挖,分层支护,围护结构的位移及横支撑的轴力均满足规范限值要求,施工安全。

Based on the Qingxiushan subway station by open-cut and subsurface excavation method with the burial depth more than 60 meters on Nanning metro line 3 in Guangxi, the effect of foundation pit dewatering on the settlement of ground surface and the effect of foundation pit excavation on the safety of retaining structure are studied. The results show that: with the increase of dewatering depth, the settlement of ground surface increase, the closer to the foundation pit and the greater the settlement of ground surface appeared;deep foundation pit are excavated and supported by layers, both of displacement of retaining structure and lateral axial force of the supports can meet the limit value of the specification to ensure the construction safety.