ABSTRACT

During tunnel excavation in hard rock, the surrounding rock could subject to dynamic loading. A huge amount of strain energy is stored in the highly stressed rock mass. After excavation, a portion of the strain energy releases rapidly and rock burst could take place. The interaction between shock waves and non-uniform stresses in the rock mass is studied in this paper. The damage extent depends on the power of the shock waves exerted on the rock surface. Owing to the rock damage caused by the shock waves, the stress concentration is shifted from the tunnel wall into the rock mass so that the risk of rock burst on the tunnel wall is reduced. Furthermore, a relatively uniform stress distribution is resulted in the surrounding rock.