盾构近距离下穿既有地铁施工风险综合控制技术

Comprehensive Risk Control Technology of Crossing Beneath the Existing Metro Lines by Shield Machine within a Short Distance

盾构法施工已成为现代地铁建设的主流工法,随着盾构施工技术与城市化的快速发展,地铁建设工况越来越复杂,地铁线路纵横交错,相互下穿,新建地铁线近距离下穿既有地铁线对施工风险高,综合控制技术难度大。为保证在建地铁线施工对既有线正常运营的安全和影响降低至最小,通过查阅类似施工成功案例,对比分析和总结应对技术措施,采用地面定向注浆加固、洞内从左线向右线钻孔定向注浆加固、洞内径向超前注浆加固3个方面的施工关键技术,结合对既有地铁线路自动化监测技术,可确保既有线正常运营安全,沉降在允许范围内。同时产生良好的经济和社会效益,可为类似工程提供借鉴和参考,推动复杂条件下城市轨道交通建设的发展。

Shield tunneling technology has become the mainstream construction method of modern metro construction.With the rapid development of shield tunneling technology and urbanization,metro construction conditions are becoming more and more complicated.Metro lines criss-cross and cross each other.The new metro line passing through the existing metro line at short distance has high construction risk and difficult comprehensive control technology.In order to ensure the safety and impact of metro line construction under construction on the normal operation of existing lines to a minimum,in order to ensure the safety and impact of subway line construction under construction on the normal operation of existing lines to the minimum,through consulting similar successful construction cases,comparative analysis and summary of technical measures,adopts three key construction technologies:ground directional grouting reinforcement,hole directional grouting reinforcement from left line to right line,and radial advance grouting reinforcement in hole,combined with automatic monitoring technology for existing subway lines,which can ensure the normal operation safety of existing lines and the settlement within the allowable range of specifications.Secondly,it can produce good economic and social benefits,which can provide reference for similar projects and promote the development of urban rail transit construction under complex conditions.