1. Associate Professor, School of Civil Engineering, Key Laboratory of Coast Civil Structure Safety of China Ministry of Education, Tianjin Univ., Tianjin 300072, China.
2. Professor, Dept. of Structural Engineering, Univ. of California, San Diego 92093, CA.
3. Professor, School of Civil Engineering, Key Laboratory of Coast Civil Structure Safety of China Ministry of Education, Tianjin Univ., Tianjin 300072, China (corresponding author).
4. Ph.D. Candidate, School of Civil Engineering, Tianjin Univ., Tianjin 300072, China.