1. Professor, Dept. of Civil Engineering, Kyungsung Univ., Busan 608-736, Korea.
2. Adjunct Professor, Dept. of Civil Engineering, Kyungsung Univ., Busan 608-736, Korea.
3. Managing Director, Musung Construction Co. Ltd., 654-2 Jeonpo-dong, Gin-gu, Busan 614-865, Korea.
4. Senior Researcher, Korea Expressway Corporation, 50-5 Sancheok-ri, Dongtan-myun, Hwasung 445-812, Korea (corresponding author).
5. Professor, Dept. of Civil Engineering, Korea Maritime Univ., Busan 606-791, Korea.