软土地区超大面积深基坑全范围同期开挖工程实践

Practice of Simultaneous Excavation of Super-large Deep Foundation Excavation in Soft Soil Area

以位于上海深厚淤泥质软土地层中的某深大基坑工程为背景,由于工期要求紧迫,结合其长矩形平面的空间特性,采用了SMW工法桩+2道钢筋混凝土内支撑的板式支护方案,配合全范围分块跳仓同期开挖施工,成功在半年内完成了从土方开挖到地下室封顶的建设目标。对基坑工程设计与施工中的关键技术进行了详细阐述,对监测结果进行了全面分析,得出一些软土地区深大基坑快速施工的工程经验与风险控制方法。

A deep and large foundation excavation located in thick silty soft ground in Shanghai is taken as an example. Because of the urgent construction duration,as well as space characteristics of the longrectangular workyard,the SMW method and two reinforced concrete bracing are used as retaining structures of the foundation excavation. Meanwhile,the simultaneous construction method is adopted,which joint with partitioned and alternative bay excavation. The basement construction is successfully completed in half a year. The key techniques of design and construction are introduced in detail. The monitoring data is analyzed in depth. Some engineering experience and risk control methods of rapid construction of deep and large foundation excavation in soft soil area are obtained.