1. Associate Professor, Dept. of Civil and Environmental Engineering, Yamaguchi Univ., 2-16-1 Tokiwadai, Ube, Yamaguchi, 755-8611, Japan (corresponding author).
2. Engineer, Yamaguchi Prefecture, Yamaguchi, Japan.
3. Project Manager, Eight-Japan Engineering Consultants, Inc., Okayama, Japan.
4. Professor, Dept. of Civil and Environmental Engineering, Pennsylvania State Univ., University Park, PA.