1. Graduate Student (JSPS Research Fellow), Dept. of Civil Engineering, Nagoya Univ., Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan. E-mail: tnakamura@nagoya-u.jp
2. Associate Professor, Dept. of Ocean Civil Engineering (Institute of Marine Industry), Gyeongsang National Univ., 445 Inpyeongdong, Tongyeong, Gyeongnam 650-160, Korea (corresponding author). E-mail: dshur@nongae.gsnu.ac.kr
3. Professor, Dept. of Civil Engineering, Nagoya Univ., Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan. E-mail: mizutani@civil.nagoya-u.ac.jp