粉细砂地层PBA工法地铁车站管幕法超前支护施工技术

Construction Technology of Pipe-curtain Advanced Support on PBAMethod Subway Station in Silty and Fine Sand Stratum

针对在粉细砂地层中,矿山法施工极易引起坍塌,而传统的超前小导管、深孔注浆、管棚等超前预支护措施,在粉细砂地层中难以达到地层加固效果的问题,结合北京地铁12号线蓟门桥站T型换乘节点进行研究,根据施工风险分析,采用管幕法超前支护方式,优化施工工艺,设计施工参数,明确施工控制要点,并经监控量测结果反馈,表明采用管幕法超前预支护,满足施工风险控制要求,同时为后续工程在粉细砂地层中管幕法超前预支护施工提供一定的参考借鉴。

The mining method construction is easy to cause the collapse in the silty and fine sand stratum.Traditional advanced measures such as small pilot tunnels,deep-hole grouting,and pipe sheds are difficult to reinforce the rock stratum.According to the construction risk analysis on the T-shaped transfer node at Jimenqiao Station on Beijing Metro Line 12,the pipe-curtain method was used to optimize the construction technology,design the construction parameters,clarify the construction control points,and provide the feedback through monitoring and measurement.It indicates that the feedback results can meet the requirements of construction risk control,and provide certain reference for the advanced pre-support construction of the pipe curtain method in the fine sand layer of subsequent projects.