1. Member, ASCE
2. Visiting Assoc. Prof., Dept. of Struct. Engrg., Univ. of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0085.
3. Prof., Dept. of Struct. Engrg., Univ. of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0085 (corresponding author). E-mail: afiliatrault@ucsd.edu