1. Postdoctoral Researcher, Dept. of Civil Engineering, South China Univ. of Technology, 381 Wushan Rd., Guangzhou 510641, PR China.
2. Professor, State Key Laboratory of Disaster Reduction in Civil Engineering and School of Civil Engineering, Tongji Univ., 1239 Siping Rd., Shanghai 200092, PR China (corresponding author).
3. Professor, Nathan M. and Anne M. Newmark Endowed Chair in Civil Engineering, Dept. of Civil and Environmental Engineering, Univ. of Illinois at Urbana-Champaign, Champaign, IL 61801.