1. Assistant Professor, Dept. of Civil and Environmental Engineering, Saitama Univ., Saitama 338-8570, Japan (corresponding author).
2. Assistant Researcher, Dept. of Civil Engineering, Fuzhou Univ., Fujian 350116, China.
3. Professor, Disaster Prevention Research Institute, Kyoto Univ., Kyoto 611-0011, Japan.
4. Director, Aoki Engineering Laboratory, Nagakute, Aichi 470-0356, Japan.