SEGJ Technical Conference

Development of geophysical survey technique using the vibration caused by the shafts excavation in the granite -Application of Reverse VSP-

Abstract A reverse VSP ,R-VSP, using the blasting vibration has been carried out to obtain three-dimensional geological image around the Mizunami Underground Research Laboratory under the shaft excavation works. In this study, the applicability of this method was discussed. As a result, several reflectors from the boundary of sediment layers and the surface of basal granite were extracted in the R-VSP profile same as the existing reflection seismic profile. For this reason, the applicability of the R-VSP to estimate the geological distribution was confirmed. R-VSP can be expected as complementary method to the reflection seismic survey, especially in the case of the restriction about layout of a seismic source on the ground surface.