Abstract:

Several water/sand gushing happened during the construction and operation of Baojiashan extralong tunnel. The geological conditions of the tunnel are presented, the causes for the water/sand gushing are analyzed and countermeasures are proposed. The principle and design of sand sediment tanks are stated and the functions of the sand sediment tanks in the treatment of the water gushing are discussed in detail. Problems and shortcomings are provided on basis of comprehensive analysis. The paper may provide reference for similar projects in the future.

Key words: Baojiashan extralong tunnel, sand sediment tank, gushing water treatment