Abstract
TFT survey is using seismic wave occurred by an excavation blasting can be carried out without interruption of tunnel excavation work. TFT survey is able to evaluate geological condition around a tunnel face in real time using direct waves. At the same time, this is able to predict geological change, for example fault or fracture zone, ahead of tunnel face trough analysis of reflect waves. As a result, much geological information can be gotten without interruption of tunnel excavation work.
This paper is reported the results of TFT survey carried out in a road tunnel construction in Japan. The changes of geological condition are estimated from the evaluation of direct waves. And the ten times of predictions ahead of the tunnel face are carried out, the results are utilized for tunnel excavation. As results, tunnelling management by seismic survey using excavation blasting is proposed.
