Abstract
Excavation of a cavern results in formation of excavation disturbed zone (EDZ) in surrounding rock. The EDZ is defined as the area where properties have been changed due to changes in the stress state and the distribution of porewater pressure. In this paper, we have proposed crack tensor model and virtual fracture model in consideration of excavation damaged zone due to blasting. These models have been applied to analyze the excavation of a shaft and drift using limited information obtained from ground surface investigations on the Mizunami Underground Research Laboratory project. As compared to the result without the excavation damaged zone, the hydraulic conductivity has increased in the surrounding rock remarkably.
