1. Graduate Research Assistant, Dept. of Civil and Environmental Engineering, Univ. of Utah, Salt Lake City, UT 84112.
2. Assistant Professor, Dept. of Civil and Environmental Engineering, Univ. of Utah, Salt Lake City, UT 84112 (corresponding author).
3. Professor, Dept. of Civil and Environmental Engineering, Univ. of Utah, Salt Lake City, UT 84112.