先填后挖法在隧道塌方中的应用

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。

The Application of Post-filling Excavation in Tunnel Collapse

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 construction is converted to underground excavation for regular tunnel weak surrounding rock. It can reduce the risks of collapse treatment to the utmost by reasonable excavation method and safety control measures.