1. Ph.D. Candidate, Dept. of Civil and Environmental Engineering, Univ. of Illinois at Urbana-Champaign, Urbana, IL 61801; Affiliated with the Dept. of Civil Engineering, King Saud Univ., Riyadh, Saudi Arabia (corresponding author).
2. Professor, Dept. of Civil and Environmental Engineering, Univ. of Illinois at Urbana-Champaign, Urbana, IL 61801.