Estimation of geological structure around underground tunnel based on cross-correlation analyses of random continuous signals from small scale core drilling

Soma, Nobukazu*; Oikawa, Yasuki*; Hirano, Toru*; Matsui, Hiroya ; Asanuma, Hiroshi*

We have studied a reflection imaging technique in which passive seismic signals from other construction activity such as drilling noise are used as a wave source in order to develop a low-cost measurement method inside underground gallery. In this paper, we show an application to data sets from Mizunami Underground Research Laboratory of Japan Atomic Energy Agency. The drilling was conducted with a main purpose of extraction rock core samples for rock mechanics research. The three-dimensional reflection imaging results and comparison with well observation are shown in this paper.