超大面积深基坑工程半逆作法施工实践

Semi-Reversed Construction Practice on Super Large Area and Deep Foundation Pit Engineering

采用地下连续墙同时兼作地下室外墙的"两墙合一"围护结构形式进行全逆作法施工,在已建工程项目中比较多见,而上海外高桥森兰商都二期超大面积深基坑工程,因地制宜,采用了非"两墙合一"的排桩围护体系半逆作法施工。实践证明,超大面积深基坑工程采用半逆作法施工,既能降低基坑围护费用、减小基坑变形,又能保护周围环境,具有良好的社会效益和经济效益。

The support structure form of ＂dual-purpose diaphragm wall＂ acted as the diaphragm wall and the basement exterior wall is used in the reversed construction method and it is very popular in the existing engineering project. However, the semi-reversed method of ＂non- dual-purpose diaphragm wall＂ row pile support system is applied to the super large and deep foundation pit excavation of Sen Lan Merchanapolis Phase II in Shanghai Waigaoqiao. The practice has proved that such construction method can not only lower the foundation pit support structure fee and reduce the deformation of foundation pit, but also can protect the surrounding environment, and has great social and economic benefits.