1. Assistant Professor, Dept. of Civil and Environmental Engineering, Univ. of California, Los Angeles, CA 90095–1593 (corresponding author).
2. Facility Manager, Center for Geotechnical Modeling, Dept. of Civil and Environmental Engineering, Univ. of California, Davis, CA 95616.
3. Professor, Dept. of Civil and Environmental Engineering, Univ. of California, Davis, CA 95616.