1. Engineer, Kobori Research Complex, Kajima Corporation, 6-5-30, Akasaka, Minato-ku, Tokyo 107-8502, Japan.
2. Professor, Dept. of Civil and Environmental Engineering, Univ. of California, Davis, CA 95616 (corresponding author).
3. Professor, Dept. of Structural Engineering, Univ. of California, San Diego, La Jolla, CA 92093.
4. Senior Associate Principal, Skidmore Owings and Merrill, 1 Maritime Plz, San Francisco, CA 94111.