1. Graduate Research Assistant, Dept. of Civil and Environmental Engineering, Louisiana State Univ., Baton Rouge, LA 70803-6405.
2. Associate Professor, Dept. of Civil and Environmental Engineering, Louisiana State Univ. Baton Rouge, LA 70803-6405 (corresponding author).
3. Associate Professor, Dept. of Civil Engineering, Univ. of Texas at Austin, Austin, TX 78758.