1. Professor, Dept. of Civil Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan (corresponding author).
2. Graduate Student, Dept. of Civil Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan.
3. Associate Professor, Dept. of Civil Engineering, Toyota National College of Technology, Sako-cho 2-1, Toyota 471-8525, Japan.