1. Senior Graduate Student, Dept. of Civil Engineering, National Chung Hsing Univ., Taichung 402, Taiwan.
2. Professor, Dept. of Civil Engineering, National Chung Hsing Univ., Taichung 402, Taiwan (corresponding author).
3. Postdoctoral Research Fellow, Dept. of Civil Engineering, National Chung Hsing Univ., Taichung 402, Taiwan.
4. Professor, Dept. of Civil Engineering, Indian Institute of Technology, Kharagpur 721302, West Bengal, India.