1. Associate Professor, Dept. of Civil Engineering, Auburn Univ., Auburn, AL 36849-5337; and Adjunct Professor, Lamar Univ., Beaumont, TX 77710 (corresponding author).
2. Project Engineer, RJR Engineering, Ltd., L. L. P., 12651 Briar Forest Dr., Suite 205, Houston, TX 77077.
3. Research Assistant, Dept. of Civil Engineering, Lamar Univ., Beaumont, TX 77710.