1. Assistant Professor, Dept. of Civil and Environmental Engineering, Univ. of Nevada, Reno, 1664 N. Virginia St., Reno, NV 89557 (corresponding author).
2. Assistant Professor, School of Civil Engineering, Chongqing Univ., Chongqing Shi, Shapingba District, Chong Qing Da Xue 400044, China.
3. Distinguished Professor, Dept. of Civil and Environmental Engineering, Univ. of California, 1 Shields Ave., Davis, CA 95616.