A Case Study on Treatment Measures for a Rock Tunnel with Inrush Mud and Sand Gushing Disaster

Shilin tunnel is a separated bi-directional four-lane highway tunnel and its distinctive geological conditions and fault structure result in frequent geological disaster like inrush mud and sand gushing. There were 6 times big scale disaster happening in an around 390m fault broken zone, the length of which is accumulatively 275m. Construction of tunnels was seriously hampered and the project was delayed and the cost increased simultaneously. During the construction of Shilin tunnel, the advanced geological forecast assured the possibility of geological disaster like inrush mud and sand gushing and then it could effectively control and decrease damage of disaster by measures of releasing energy, lessening pressure, grouting cement, advanced support, comprehensive treatment. Meanwhile, those measures maximally strengthen fractured surrounding rocks, assured safety of construction. This way is effective for like inrush mud and sand gushing under similar conditions, this successful experience will apply reference for similar projects.