Groundwater exploration method in the ground in front of the tunnel

摘要

PPROBLEM TO BE SOLVED: To provide a method of exploration for groundwater in tunnel ahead ground with low cost and in short time within a relatively long range of substantially 50-100 m ahead from a tunnel pit. PSOLUTION: The groundwater exploration method estimates the state of groundwater of tunnel ahead ground by forming an substantially vertical boring hole 18 from the ground surface 16 to ground 17 of a tunnel ahead ground face 11, and arranging electrodes 18a on a plurality of places in the boring hole; or by arranging electrodes on a plurality of places in an existing boring hole already formed from the ground surface to the ground ahead of the tunnel face and, in the tunnel, forming boring holes 14 and 15 perpendicular to the tunnel axis around or a predetermined length behind the face, and arranging electrodes 14a and 15a on a plurality of places in the boring hole, and determining resistivity between the electrodes 18a and the electrodes 14a, 15a. PCOPYRIGHT: (C)2009,JPO&INPIT