ABSTRACT
The stress wave induced by an underground explosion usually propagates in a spherical or cylindrical form and relates to the charge loading density, the chamber geometry and the rock mass properties. An explosive wave consists of a shock wave and a pressure wave with high frequency. Since the rock mass is a discontinuous media and filled with many joints, the explosion-induced wave propagation in a rock mass is a very complex process (King et al. 1986). Wave attenuation is related to the geometrical spreading and material damping (Dowding 1996). From field tests, it was found that the explosion-induced wave propagation in jointed rock mass highly depends on the material damping ratio (Worthington et al. 2001). When the waves arrive at the ground, the reflected body waves and surface waves are synchronously caused. Besides the rock mass, the ground motion characteristics are also affected by the presence of an overburden soil layer. For simplification, only the rock mass is considered as the burden of the underground facility in the present study.
