1. Graduate Student, Dept. of Civil and Environmental Engineering, Pennsylvania State Univ., University Park, PA 16802.
2. Associate Professor, Dept. of Civil and Environmental Engineering, Pennsylvania State Univ., University Park, PA 16802 (corresponding author).
3. Associate Professor, Dept. of Civil and Environmental Engineering, Pennsylvania State Univ., University Park, PA 16802.
4. Research Geotechnical Engineer, Turner Fairbank Highway Research Center, Federal Highway Administration, 6300 Georgetown Pike, McLean, VA 22101.