1. Associate Professor Earthquake Research Institute, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 1130032, Japan e-mail:
2. Research Fellow of the Japan Society for the Promotion of Science (DC), Department of Civil Engineering, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 1130032, Japan e-mail:
3. Professor Earthquake Research Institute, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 1130032, Japan e-mail:
4. Researcher Tokyo Gas Co., Ltd., 1-7-7 Suehiro-cho, Tsurumi-ku, Yokohama 2300045, Japan e-mail:
5. Researcher Tokyo Gas Co., Ltd., 1-5-20 Kaigan, Minato-ku, Tokyo 1058527, Japan e-mail: