1. Graduate Research Assistant, Dept. of Civil and Environmental Engineering, Louisiana State Univ., 3418 Patrick F. Taylor Hall, Baton Rouge, LA 70803.
2. Professor, Dept. of Civil and Environmental Engineering, Louisiana State Univ., 3418 Patrick F. Taylor Hall, Baton Rouge, LA 70803 (corresponding author).
3. Lecturer, Dept. of Civil Engineering, Univ. of New Hampshire, W139 Kingsbury Hall, 33 Academic Way, Durham, NH 03824.
4. Associate Professor, Dept. of Mathematics, Statistics and Mechanical Engineering, Louisiana Tech Univ., Bogard Hall 226, Ruston, LA 71272.