1. Assistant Professor, Dept. of Bridge Engineering, Tongji Univ., Shanghai 200092, China (corresponding author).
2. Professor, Dept. of Civil and Environmental Engineering, Rutgers, State Univ. of New Jersey, Piscataway, NJ 08854.
3. Visiting Assistant Professor, Dept. of Civil and Environmental Engineering, Lamar Univ., Beaumont, TX 77710.