1. Ph.D. Candidate, Dept. of Civil Engineering, 362D Whittier Research Center, Univ. of Nebraska, Lincoln, NE 68583, US, e-mail: sooim@huskers.unl.edu
2. Associate Professor, Dept. of Civil Engineering, 224 Engineering Building, Kyung Hee Univ., Yongin-si, Gyeonggi-do 446-701, KR (Corresponding author), e-mail: ykim3@khu.ac.kr
3. Post-doctoral Research Associate, Dept. of Civil Engineering, 362H Whittier Research Center, Univ. of Nebraska, Lincoln, NE 68583, US, e-mail: hban2@unlnotes.unl.edu