1. Ph.D. Student, School of Civil and Environmental Engineering, Georgia Institute of Technology, 790 Atlantic Dr. N.W., Atlanta, GA 30332-0355 (corresponding author).
2. Associate Professor, Zachry Dept. of Civil Engineering, Texas A&M Univ., 3136 TAMU, CE/TTI Building, College Station, TX 77843-3136.
3. Associate Professor, School of Civil and Environmental Engineering, Georgia Institute of Technology, 790 Atlantic Dr. N.W., Atlanta, GA 30332-0355.