1. Graduate Research Assistant, Dept. of Civil Engineering, Texas A&M Univ., TAMU 3135, College Station, TX 77843 (corresponding author).
2. Professor, Dept. of Civil Engineering, Texas A&M Univ., TAMU 3135, College Station, TX 77843.
3. Assistant Professor, Dept. of Civil, Architectural, and Environmental Eng., 1 Univ. Station C1761, Univ. of Texas at Austin, Austin, TX.