深圳新机场T3航站楼泵站深基坑支护设计与监测分析

深圳机场交通市政第二合同段污水提升泵站围绕T3航站楼有东、西、南三个,在施工过程中其基坑需开挖8～10m,由于地面以下有深厚的海积超软弱淤泥层,基坑采用钻孔桩+桩间单管旋喷桩+一道钢管内支撑+C20喷射混凝土护壁的支护方案,施工难度较大,为保证基坑施工安全,在基坑支护工程和主体工程施工的各个阶段,对支护结构的变形进行监测。通过监测支护结构的变形参数,证明该支护方案较适合深厚海积超软淤泥层的基坑支护工程。

Excavation Monitoring for Proposed Lift Pump Stations Around the Terminal 3 of the Shen Zhen New Airport

Contract No.2 of the Shen Zhen Airport Transport Services project involved a total of three（3） lift pump stations being proposed at the east,west and south side of the ＂ Terminal 3＂,respectively.The construction required 8-10 meter deep excavations.Due to the large presence of the very soft silt and clay marine deposits,the excavations were sustained utilizing a piling system consisting of drilled shafts with mono-tubed churning piles in between.Additionally,a layer of steel pipe internal brace with C20 shotcrete was used to further maintain the stability.These multiple measures added challenges to the construction.For safety concerns,a monitoring program was conducted during each stage of the excavation and shoring installation,as well as during each individual construction period of the overall project.The monitoring efforts were focused on the deformation of the shoring system.Results based on the monitoring data showed that such a comprehensive supporting system may be suitable for deep excavations through marine deposits that are typically featured with very soft silt and clays.