1. Ph.D. Student, Dept. of Civil Engineering, Univ. of Texas at Arlington, 425 Nedderman Hall, 416 Yates St., Arlington, TX 76019.
2. Assistant Professor, Dept. of Civil Engineering, Univ. of Texas at Arlington, 425 Nedderman Hall, 416 Yates St., Box 19308, Arlington, TX 76019 (corresponding author).