1. Assistant Professor, Key Laboratory of Coast Civil Structure Safety of Ministry of Education, Tianjin Univ., Tianjin 300-072, China; formerly, Postdoctoral Fellow, Disaster Prevention Research Institute, Kyoto Univ., Gokasho, Uji, Kyoto 611-0011, Japan (corresponding author).
2. Lecturer, Faculty of Environmental Engineering, Univ. of Kitakyushu, Hibikino, Wakamatsu-ku, Kitakyushu, Fukuoka 808-0135, Japan.
3. Assistant Professor, Dept. of Architecture and Civil Engineering, Toyohashi Univ. of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, Aichi 441-8580, Japan.
4. Professor, Disaster Prevention Research Institute, Kyoto Univ., Gokasho, Uji, Kyoto 611-0011, Japan.