Abstract: After the TBM boring in the exit end of the Gaoligongshan tunnel of the DaliRuili railway at section D1K224+200~+230, sudden water and mud outburst occur, which leads to tunnel collapse, TBM jam, and belt conveyor stop. As a result, the causes for water and mud outburst are analyzed, and a series of techniques such as surface river channel repair, collapse cave backfilling, and deephole grouting reinforcement are conducted to guarantee the tunnel roof stability and prevent water inrush based on treatment experience of water and mud outburst in waterrich fullyweathered granite. Meanwhile, the grouting reinforcement retailing walls are conducted on both sides of water and mud outburst point to provide safety guarantee for mud clearing and TBM reboring. A treatment scheme of highlevel lock, discharge and depressurization, twoend stop, support strengthening, and fastexcavation and fast seal is formed, which has successfully solved the water and mud outburst in tunnel in waterrich weathered granite.

Key words: Gaoligongshan tunnel,  , TBM, water and mud outburst, surface seepage control, reinforced retaining wall, highlevel lock, discharge and depressurization