浅埋偏压桥隧相接隧道出洞施工技术

受隧道洞口地质、地形条件的限制,山岭隧道选择出洞施工的情况逐渐增多,相应的技术要求也越来越高。安康至岚皋高速公路长春隧道出口端位于浅埋偏压山体以及桥隧相接处,且一侧下方紧邻S207省道,故在选择出洞施工时,通过修筑挡墙、搭设防护棚和实施交通管制等措施确保S207省道行车安全,采用小导洞出洞,经由它将机械、人员送出洞外,进行边仰坡开挖及防护施工;洞外管棚施作完成后,由内向外采取环形预留核心土法贯通,保障了隧道出洞施工的安全。

Construction Technology for Portal of Shallow and Asymmetrically Loaded Tunnel Connecting Bridge

Due to the limitation of the geological and topographical conditions of the tunnel,the application of construction technology for the portal has gradually increased,and the technical requirements become higher and higher.The exit end of Changchun Tunnel of Ankang-Langao Expressway is located at the shallow and asymmetrically loaded mountain that connects a bridge,and the S207 provincial highway is located below one side.Therefore,in order to ensure the safety of S207 traffic during the construction,measures such as building retaining walls,setting up protective sheds and implementing traffic control were applied.A small pilot tunnel was used to exit the tunnel,through which machinery and personnel were sent out of the tunnel for side slope excavation and protection.After the construction of the pipe shed outside the tunnel was completed,the ring-cut excavation was carried out from the inside to the outside to ensure the safety of the tunnel portal.