1. Professor, Dept. of Civil Engineering, Nihon Univ., College of Science and Technology. Kanda Surugadai 1-8-14 Chiyoda-ku, Tokyo, 101-8308, Japan.
2. Associate Professor, Dept. of Civil Engineering, Nihon Univ., College of Science and Technology, Tokyo, Japan.
3. Research Associate, Dept. of Civil Engineering, Nihon Univ., College of Science and Technology, Tokyo, Japan.