正交转换通道暗挖隧道群快速施工技术研究

Research on rapid construction technology of orthogonal conversion channel undercut tunnel group

地铁区间共建段道岔区正交转换通道隧道群正交隧道断面多、断面大、隧道之间小净距岩柱薄,地铁隧道埋深一般较浅,地表建筑密集,合理的施工工法能提高施工效率确保施工安全。依托重庆轨道交通10号线兰南区间大里程区间共建段道岔区正交转换通道隧道群施工,进行了隧道群施工工法的优化研究。工程实践表明:隧道群施工需提前做好各作业面施工顺序及施工方法研究,科学合理的施工顺序及施工方法能在确保施工安全的前提下提高施工效率;大断面双侧壁导坑核心土不同拆除工法对施工安全及施工效率影响较大;隧道群小净距采用合理的开挖顺序及开挖方式、优化支护措施能保证施工安全。

The orthogonal conversion channel tunnel group in the turnout area of the subway section joint construction section has multiple cross sections,large cross sections,and small clear distance between tunnels with thin rock columns.The buried depth of subway tunnels is generally shallow,and the surface buildings are dense.Reasonable construction methods can improve construction efficiency and ensure construction safety.Based on the construction of the orthogonal conversion channel tunnel group in the turnout area of the large mileage section of the Lannan section of Chongqing Metro Line 10,optimization research on the construction method of the tunnel group was carried out.Engineering practice has shown that the construction of tunnel groups requires early research on the construction sequence and methods of each working face.Scientific and reasonable construction sequence and methods can improve construction efficiency while ensuring construction safety;the different demolition methods for the core soil of the large cross-section double-sided guide pit have a significant impact on construction safety and efficiency;reasonable excavation sequence and method,as well as optimized support measures,can ensure construction safety with a small clear distance in the tunnel group.