Investigation of blast-induced fracture in rock mass using reversed vertical seismic profiling

The rock mass on quarry and pit wall surfaces is usually fractured during p roduction blasting. Quantitative investigations of the fractured zones are needed for stabilization of the rock walls. In this study, the principle of reversed vertical seismic profiling (RVSP) was applied. A set of seismic g eophones were arranged on the horizontal bench surface and seismic signals were generated along the vertical rock wall using a free-swinging hammer. T he travel times of seismic rays were recorded and the P-wave velocities of the rock mass were analyzed using the Simultaneous Iterative Reconstruction Technique (SIRT). A series of site tests have been carried out on the rock walls at a granite quarry that are characterized by fractures. The fractur e depth at various locations on the wall surface is thereby determined. The results indicate that RVSP provides an easy and reliable method to quantit atively evaluate the blasting-induced fractures in the rock mass. (C) 2001 Published by Elsevier Science B.V.