山地城市暗挖隧道近距离下穿桥梁施工技术研究与应用

Research and Application of Construction Technology of Short Distance Mined Tunnel Crossing Bridge in Mountainous City

针对贵阳典型的山镇复杂环境下地铁下穿既有建(构)筑物的施工难题,在确定采用冷开挖施工方法的基础上,模拟了区间隧道左线先行和右线先行2种下穿既有桥梁方案的施工过程,确定了左线先行的技术方案,即先进行左隧下穿段施工,其二次衬砌施工完成后,再进行右隧下穿段施工。对该施工过程控制要点进行了总结,并对施工中桥墩沉降及其倾斜的监测数据进行分析,该方法可减少隧道开挖时对周边环境的扰动,降低施工风险,保证既有立交桥运营安全。

Focusing on the construction problem of subway undercrossing existing buildings in the complex environment of typical mountain town-Guiyang,on the basis of determining excavation method,two types of construction processes of undercrossing existing bridge are simulated.Finally,the technical scheme of the tunnel left line first crossing is determined.The key points of the construction process control are summarized,the monitoring data of settlement and inclination of pier column is analyzed.The scheme can reduce the disturbance to the surrounding environment,reduce the construction risk and ensure the safety of bridge operation.