1. Research Environmental Engineer, Research Triangle Institute, 3040 Cornwallis Road, Box 12194, Research Triangle Park, NC 27709-6506.
2. Manager, ABB Inc., 208 South Rogers Lane, Raleigh, NC.
3. Research Assistant, Dept. of Civil Engineering, North Carolina State Univ., Box 7908, Raleigh, NC 27695.
4. Associate Professor, Dept. of Civil Engineering, North Carolina State Univ., Box 7908, Raleigh, NC 27695 (corresponding author).
5. Professor and Associate Head, Dept. of Civil Engineering, North Carolina State Univ., Box 7908, Raleigh, NC 27695.
6. Professor and Head, Dept. of Civil Engineering, North Carolina State Univ., Box 7908, Raleigh, NC 27695.