1. Chief Researcher, Korea Bridge Design and Engineering Research Center, Seoul, Korea; Dept. of Civil Engineering, Lehigh Univ., Bethlehem, PA 18015 (corresponding author).
2. Professor, Dept. of Civil and Environmental Engineering, Seoul National Univ., Seoul, Korea; Dept. of Civil Engineering, Univ. of Illinois Champaign, Champaign, IL.
3. Professor, Dept. of Architectural Engineering, Seoul National Univ., Seoul, Korea; Dept. of Civil Engineering, Lehigh Univ., Bethlehem, PA 18015.