1. Graduate Student, Zachry Dept. of Civil Engineering, Texas A&M Univ., College Station, TX 77843-3136.
2. Associate Professor, Zachry Dept. of Civil Engineering, Texas A&M Univ., College Station, TX 77843-3136 (corresponding author).
3. Professor, Zachry Dept. of Civil Engineering, Texas A&M Univ., College Station, TX 77843-3136.
4. Buchanan Chair Professor, Zachry Dept. of Civil Engineering, Texas A&M Univ., College Station, TX 77843-3136.