特殊土・その他

[III-351] Laser based Remote evaluation of sound speed in rocks

〇suzuki ken-ichirou¹, Okuzawa Koichi¹, Shinmura Akira¹, Taniguchi Nobuhiro¹, Shimada Yoshinori² (1.Obayashi Corporation, 2.Institute for Laser Technology)

Keywords:Laser, elastic wave velocity, rocks

If laser impact will initiate acoustic wave in rock and laser vibration sensor will detect acoustic wave propagating through corresponding rock from ten several meters distant places, it becomes possible to reduce the risk in entering the danger region for geological and sounding survey of rock surfaces. In this laboratory tests of seven rock samples of five rock types, a pulsed laser is used as a source of laser impact and laser vibration meter is used as detector. As the results, laser-based evaluation of sound speed in rocks is same as piezometric material-based evaluation and the speed of surface wave is corresponding to that of transmitted wave.