CSM工法等厚度水泥土搅拌墙在紧邻既有建筑深基坑工程中的应用

Application of constant thickness steel cement-soil wall constructed by CSM method in deep excavation adjacent to existing buildings

上海老年医学中心项目为既有建筑改造项目,其基坑区域普遍开挖深度为18.15 m,开挖过程中面临承压水大幅度抽降。基坑周边环境复杂,东南侧紧邻已建成的5~#楼,南侧邻近4~#楼地下室,北侧邻近需要重点保护的居民建筑。基坑支护结构采取了地下连续墙结合4道钢筋混凝土水平临时支撑,并采用了CSM工法构建的等厚度水泥土搅拌墙作为悬挂隔水帷幕。工程实践结果表明,通过采取上述技术措施,本工程地下空间开发对周边环境影响可控,确保了周边环境的安全。本工程采取的设计、施工技术措施和监测结果可为今后类似地下空间开发工程提供借鉴。

Shanghai Geriatrics Center Building is a reconstruction project of existing building.The deep excavation,which the depth is 18.15 m in general region,needs a large scale dewatering of confined water.The environment protection is serious,which is adjacent to building 5~#on the south-east side,the basement of building 4~#on the south side,and a residential building on the north side.Four horizontal temporary reinforced concrete bracings system combined with diaphragm wall are used as excavation supporting system,and constant thickness cement-soil wall constructed by CSM(cutter soil mixing technology)is used as suspended water proof wall.From the construction and practice of the engineering,it shows that the influence of the deep excavation is under control and the surrounding environment is safe through above technique measures.The design and construction measures can give available guidance for relevant development of underground space.