1. Assistant Professor, Dept. of Civil, Environmental, and Architectural Engineering, Univ. of Kansas, 1530 W. 15th St., 2150 Learned Hall, Lawrence, KS 66045 (corresponding author).
2. Professor, Dept. of Civil, Environmental, and Architectural Engineering, Univ. of Colorado, 428 UCB, 1111 Engineering Dr., Boulder, CO 80309-0428.