先填后挖法在隧道塌方中的应用

摘要

在隧道埋深较大位置出现大塌方，地表无法直接注浆回填和明挖时，选用具有较好流动性的轻质混凝土材料，超前灌筑满塌方顶部空腔及固结已塌方的石碴，同时设置超前大管棚贯通整个塌方体，将塌方段处理转换成隧道常规的软弱围岩暗挖施工，通过采用合理的开挖工法和安全控制措施，极大降低了塌方处理的风险。%When big collapse occurs in deep buried tunnel and there is no condition for backfill grouting or cut &cover tunnels,light concrete with good liquidity should be used to pre-grout the top empty cavity and consolidate the collapse slag fully;meanwhile,the advanced large pipe shed should be set through the whole collapse.In this way,the collapse con-struction is converted to underground excavation for regular tunnel weak surrounding rock.It can reduce the risks of col-lapse treatment to the utmost by reasonable excavation method and safety control measures.