1. Doctoral Candidate, Dept. of Civil and Environmental Engineering, Univ. of Illinois at Urbana Champaign, 205 North Mathews Ave, Urbana, IL, 61801; formerly, Graduate Student, Univ. of Tokyo, Tokyo 113-8656, Japan.
2. PhD, Bridge Maintenance Consultant Corp., WBG Marive West, 25th Floor, Nakase 2-6, Mihama-ku, Chiba 261-7125, Japan.
3. PhD, Professor, Dept. of Civil Engineering, Univ. of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-8656, Japan (corresponding author).
4. General Manager, Structures Division, Civil Engineering Research Institute of Hokkaido, 1-34, Higashi 1-3, Toyohira-ku, Sapporo 062-8602, Japan.