1. Graduate Student Researcher, Dept. of Structural Engineering, Univ. of California, San Diego, La Jolla, CA 92093-0085. ORCID: .
2. Professor, Dept. of Structural Engineering, Univ. of California, San Diego, La Jolla, CA 92093-0085 (corresponding author). ORCID: .
3. Professor, Dept. of Civil Engineering and Architecture, Tokyo Institute of Technology, Tokyo, Kanagawa 226-8503, Japan.
4. Engineer, Tokyo Soil Research Co., Ltd., Umezono, Tsukuba 305, Japan.