1. School of Civil and Environmental Engineering, Cornell Univ., 300 Boren Ave. N, Seattle, WA 98109 (corresponding author).
2. Professor, School of Civil and Environmental Engineering, Cornell Univ., 220 Hollister Dr., Ithaca, NY 14853.
3. Professor, Ingram School of Engineering, Texas State Univ., 601 University Dr., San Marcos, TX 78666.
4. School of Civil and Environmental Engineering, Cornell Univ., 220 Hollister Dr., Ithaca, NY 14853.