Abstract
In the present paper, an accurate imaging technique for looking ahead of tunnel face by use of 3 components receivers is proposed.
The reconstruction procedures of geological structure are as follows.
1) To receive the reflected waves from the geological boundaries by use of 3 components receivers.
2) To detect the incident direction of reflected waves.
3) To perform imaging by use of equi-travel time planes using the weight according to incident direction in order to decrease the generation of false image.
The proposed technique was applied to the actual field data. Consequently, the imaging results showed a good agreement with the observation report after completion of tunnel.
