Journal of the Korean Society of Mineral and Energy Resources Engineers ISSN:2288-0291(Print) 2288-2790(Online) 한국자원공학회지

In this study, 3D Kirchhoff migration technique was performed to investigate its feasibility of the application to tunnel detection. For the seismic data acquisition, side-line array which can be classified into one of the typical cross-hole array was implemented to minimize the loss and distortion of diffraction signal caused by tunnel. We acquired three cross-hole seismic data sets from 4 boreholes located around the tunnel. In the pre- processing stage, to remove the unwanted events and to extract the diffraction signal, median filtering was applied for the suppression of tube and primary S event. Other events such as primary P wave and mode-converted events which separated in time with respect to diffraction signal were eliminated simply by surgical muting. We extracted vertical and horizontal migration images based on 3D kirchhoff migration technique. From these results, we concluded that migration technique has enough potential of application to tunnel detection. In addition, it is also necessary to perform the further experiment and discussion by employing the seismic S-wave source and three component borehole geophone.