1. Professor, College of Civil Engineering, Northeast Forestry Univ., No. 26 Hexing Rd., Xiangfang District, Harbin 150040, P.R. China; currently, Postdoctoral Fellow, School of Civil Engineering, Beijing Jiaotong Univ., No. 3, Shangyuancun, Xizhimenwai, Beijing, 100044, P.R. China.
2. Assistant Professor, Univ. of Colorado, Denver, CO 80217 (corresponding author); currently, Guest Professor, College of Civil Engineering, Northeast Forestry Univ., No. 26 Hexing Rd., Xiangfang District, Harbin 150040, P.R. China.
3. Professor, School of Civil Engineering, Beijing Jiaotong Univ., No. 3, Shangyuancun, Xizhimenwai, Beijing, 100044, P.R. China.
4. Professor, College of Civil Engineering, Northeast Forestry Univ., No. 26 Hexing Rd., Xiangfang District, Harbin 150040, P.R. China.