1. Guangzhou HKUST Fok Ying Tung Research Institute; Guangzhou 511458 China
2. Dep. of Civil and Environmental Engineering; Hong Kong Univ. of Science and Technology; Kowloon Hong Kong
3. Shenzhen Key Lab. of Urban and Civil Engineering for Disaster Prevention and Mitigation; Shenzhen Graduate School, Harbin Institute of Technology; Shenzhen 518055 China