砂卵石地层中暗挖地铁车站止水方案研究

Research on Water Stop Scheme of Underground Excavation Subway Station in Sandy Cobble Stratum

随着地下工程建设环境越来越复杂,轨道交通建设已由浅部地层向深部地层发展。在含水量丰富的深部砂卵石地层中修建地铁车站,暗挖堵水技术的可靠性是土建安全施工的关键。本文针对北京某地铁站存在含水量丰富的厚卵石地层特点,对在该地层进行暗挖施工堵水方式进行探讨,提出一种PBA暗挖车站洞内咬合排桩和底板冻结体相结合的止水方案,并对该方案的技术难点、工艺措施进行了分析研究,以期为同类型暗挖地铁车站地下水处理提供参考。

As the environment of underground engineering becomes more and more complicated,the transportation construction has developed from the shallow stratum to the deep one.When building a subway station in the deep sandy cobble stratum with rich moisture content,the technology of underground excavation and water blocking is the key to the feasibility of civil engineering.Aiming at the characteristics of a thick pebble stratum with rich moisture content in the subway in Beijing,this paper presents the method of blocking groundwater for subsurface excavation,and proposes a waterstop plan with combining the secant piles in row in the cave and the frozen body of the bottom plate.In the meantime,the technical difficulties and treatment measures of the scheme are analyzed and studied in the following part,with a view to providing reference for groundwater treatment in the same type of underground excavation subway station.