1. Graduate Research Assistant, Dept. of Civil, Environmental and Architectural Engineering, Univ. of Colorado Boulder, Boulder, CO 80309.
2. Graduate Research Assistant, Dept. of Civil Engineering, Univ. of British Columbia, Vancouver, BC, Canada V6T 1Z4.
3. Graduate Research Assistant, Dept. of Civil and Environmental Engineering, Univ. of Washington, Seattle, WA 98195.
4. Associate Professor, Dept. of Civil, Environmental and Architectural Engineering, Univ. of Colorado Boulder, Boulder, CO 80309 (corresponding author).
5. Associate Professor, Dept. of Civil Engineering, Univ. of British Columbia, Vancouver, BC, Canada V6T 1Z4.
6. Associate Professor, Dept. of Civil and Environmental Engineering, Univ. of Washington, Seattle, WA 98195.