紧邻上海黄浦江的深大基坑工程设计与实践

Design and Practice of Deep Excavation Engineering Adjacent to the Huangpu River in Shanghai

上海属于软土地区,淤泥质土厚,地下水位高,而沿黄浦江两岸浅层分布有江滩土,该土层以粉性土为主,局部夹较多的淤泥质黏性土,土质不均匀且压缩性大,与上海常规地区土性不尽相同。以上海合景国际广场项目深基坑工程为背景,介绍了紧邻黄浦江深基坑工程支护结构的选型分析思路,针对在江滩土条件下大直径钻孔灌注桩结合三轴水泥土搅拌桩止水帷幕的施工、支撑与栈桥结合的设计以及降排水和土方开挖的方式等关键问题提出相应的技术措施。实施与监测结果表明,基坑支护设计和整个实施过程达到预期的目标,较好的保护周边环境,可为软土地区同类工程提供参考。

Shanghai is in soft soil area,which has thick silt soil and high underground water level.But along both sides of the Huangpu River,it has marshland soil in the shallow,which contains silty soil predominantly,and some areas contain much silk clay,the soil fabric is nonuniform and has high compressibility character in this area,different with the conventional regional soil in Shanghai.Taking the deep excavation projects of Shanghai Hejing International Plaza as the background,this paper introduces the selection and analysis ideas of supporting structure in deep excavation engineering which adjacent to the Huangpu River.Some special technologies has adopted in this project,including the construction of large diameter bored castin-place piles and waterproof curtains in marshland soil region,the design of the trestle bridge support system,the method of dewatering and excavation.The monitoring results show that the procedure of construction is safe and the deformation of surrounding facilities is under control.These solutions provide good reference for other similar projects in soft soil regions.