1. Postdoctoral Fellow, Civil and Environmental Engineering, Univ. of South Carolina, 300 S. Main St., Columbia, SC 29208.
2. Mr. and Mrs. Irwin B. Kahn Professor and Chair, Civil and Environmental Engineering, Univ. of South Carolina, 300 S. Main St., Columbia, SC 29208.
3. Associate Professor, Faculty of Engineering at Mataria, Helwan Univ., Cairo, Egypt.