Tunnel excavation using the geologicalconditions by reflection seismic survey

When the tunnel is long such as some few kilometers in length, the tunnel tends to situate deeply under the ground. We can't investigate the geological conditions correctly on the ground surface, so try to investigate them in the tunnel. We studied the tunnel about 1,100m long before excavation, and investigated surrounding rock by using the reflection seismic survey. TSP (Tunnel Seismic Prediction) is one of some reflection seismic surveys, we set several shot points (24 points usually), one receiver and a recorder (PC), and pick up the reflection seismic wave occurred at reflector. Then we analyze the reflection seismic wave, and we can predict the geological conditions by reflector in the front of tunnel face about 100 in. in 1.5 day. At last, the geological conditions have been understood and the tunnel could be constructed successfully by using the reflection seismic survey in the aspect of tunnel supports and the safe control, also in the prediction of the physical properties.