1. Professor, Dept. of Civil Engineering, National Chung Hsing Univ., Taichung 402, Taiwan, Republic of China (corresponding author).
2. Senior Graduate Student, Dept. of Civil Engineering, National Chung Hsing Univ., Taichung 402, Taiwan, Republic of China.
3. Postdoctoral Research Fellow, Dept. of Civil Engineering, National Chung Hsing Univ., Taichung 402, Taiwan, Republic of China.
4. Dept. of Civil Engineering, National Chung Hsing Univ., Taichung 402, Taiwan, Republic of China.
5. Professor, Dept. of Civil Engineering, K. L. E. S. College of Engineering and Technology, Belgaum 590008, India.