浅埋暗挖法地铁隧道下穿构筑物变形控制研究

Study on Deformation Control of Shallow Buried Excavation Subway Tunnel Passing through Important Structures from below

随着城市轨道交通建设不断发展,新建线路下穿城市重要建(构)筑物十分普遍。为有效控制因地面沉降引起的地层变形,以北京地铁新机场线下穿在役燃气调压站为例,通过CAESAR II及MIDAS GTS两种软件进行建模分析、超前地质加固及实时监控量测等手段,对超前大管棚+超前深孔注浆+初支背后回填注浆相结合的开挖方式下穿燃气调压站施工进行了研究。结果表明:超前大管棚对控制地层沉降起到棚护作用;深孔注浆对控制地层沉降起到主导作用;初支背后回填注浆对控制地层沉降起到补偿作用;最终地层变形值控制在允许范围内。研究成果可为今后类似工程提供一定参考。

With the continuous development of urban rail transit construction,it is widespread for new lines to penetrate the important buildings(structures)in the city.To effectively control the ground deformation caused by land subsidence,this paper took the new airport line of Beijing Metro as an example.Through two kinds of software modeling analysis in cluding CAESAR II and Midas GTS,advanced geological reinforcement,real-time monitoring and measurement,and the excavation method of the combination of advanced large pipe shed+advanced deep hole grouting+backfill grouting behind the initial support through the gas pressure regulating station construction are studied.The results show that:the advance large pipe shed plays a role of shed protection in the control of stratum settlement;the deep hole grouting plays a leading role in the management of stratum settlement;the backfill grouting behind the initial support plays a compen sation role in the control of stratum settlement;the final stratum deformation value will be controlled within the allow able range.The research results can provide some reference for similar projects in the future.