1. Dept. of Civil Engineering, Univ. of Minnesota, 500 Pillsbury Dr. S. E., Minneapolis, MN 55455; and Senior Researcher, Samsung Construction and Technology Corporation, 6th Floor, Daeryung Gangnam Tower 826-20, Yeoksam 1-Dong Gangnam-Gu, Seoul 135-935, South Korea (corresponding author).
2. Associate Professor, Dept. of Civil Engineering, Univ. of Minnesota, 500 Pillsbury Dr. S. E., Minneapolis, MN 55455.
3. Scientist, Dept. of Civil Engineering, Univ. of Minnesota, 500 Pillsbury Dr. S. E., Minneapolis, MN 55455.