1. Ph.D. Candidate, Dept. of Structural Engineering, Univ. of California at San Diego, La Jolla, CA 92093.
2. Professor, Dept. of Structural Engineering, Univ. of California at San Diego, La Jolla, CA 92093 (corresponding author).
3. Professor, Dept. of Civil and Environmental Engineering, Univ. of California, Davis, CA 95616.
4. Ph.D. Student, Dept. of Civil and Environmental Engineering, Univ. of California, Davis, CA 95616.
5. Professor, Dept. of Civil Engineering, Santa Clara University, Santa Clara, CA 95053.