1. Postdoctoral Research Associate, Dept. of Civil and Environmental Engineering, Univ. of Illinois at Urbana-Champaign, Urbana, IL 61801 (corresponding author).
2. Donald Biggar Willett Professor of Engineering, Dept. of Civil and Environmental Engineering, Univ. of Illinois at Urbana-Champaign, Urbana, IL 61801.
3. Professor and Narbey Khachaturian Faculty Scholar, Dept. of Civil and Environmental Engineering, Univ. of Illinois at Urbana-Champaign, Urbana, IL 61801.