The Application Test of the Method for the Survey of Underground Openings }using Microtremors} -Application to Underground Openings of a Closed Mine-

Ueda, Minoru*; Hashizume, Masahiro *

We are developing the method of prospecting underground openings using microtremors around our service area in order to prospect underground openings of closed lignite mines effectively at Electric Power Research & Development Center of CHUBU Electric Power Co.,Inc. We have few results in the mountainous area. So we made the field survey preliminary to inspection of the application of the method at the formar Yotsugi open-pit in Ningyo- toge Environmental Engineering Center. We also tried two dimensions numerical analysis in order to reproduce results of measurement of microtremors there.As a result it could be confirmed that the results of analysis were harmonious with those of measurements, in which velocity spectrums on measurement points changed remarkably in the symmetry shape with respect to the point above the openings along the measurement lines while they didn't change along the measurement lines with backfilled underground openings.Therefore it could be confirmed that it was able to judge the situation of falling ground above openings on this point by using microtremors.