1. Associate Professor, Dept. of Civil Engineering, Korea Maritime Univ., #1 Dongsam-Dong, Yeongdo-Gu Busan, 606-791 South Korea.
2. Researcher, Daewoo Inst. of Construction Technology, Daewoo Engineering & Construction Co., Ltd., 60 Songjuk Jangan Suwon Kyonggi 440-210, South Korea.
3. Postdoctoral Research Fellow, Dept. of Civil, Architectural, and Environmental Engineering, Missouri Univ. of Science and Technology, Rolla, MO 65409 (corresponding author).
4. Associate Professor, Dept. of Civil Engineering, National Taiwan Univ. 10617, Taiwan.