1. Assistant Professor, Dept. of Civil Engineering, IIT Madras, Chennai 600 036, India (corresponding author).
2. Assistant Professor, Dept. of Civil Engineering, North Carolina State Univ., Campus Box 7908, Room 424B, Mann Hall, Raleigh, NC 27695-7908.
3. Keith W. Klaasmeyer Chair in Engineering and Technology, Dept. of Civil Engineering, Univ. of Nebraska, W348 Nebraska Hall, P.O. Box 880531, Lincoln, NE 68588-0531.