1. Graduate Research Assistant, Dept. of Civil Engineering, 238 Harbert Engineering Center, Auburn Univ., AL 36849 (corresponding author).
2. Graduate Research Assistant, Dept. of Civil Engineering, 238 Harbert Engineering Center, Auburn Univ., AL 36849.
3. Arthur H. Feagin Chair Professor, Dept. of Civil Engineering, 238 Harbert Engineering Center, Auburn Univ., AL 36849.