1. Ph.D. Candidate and Graduate Research Assistant, Dept. of Civil, Architectural, and Environmental Engineering, Univ. of Texas at Austin, 1 University Station, Austin, TX 78712.
2. Garry Neil Drummond Chair in Engineering, Dept. of Civil, Construction, and Environmental Engineering, The Univ. of Alabama, 262 H. M. Comer Hall, Box 870205, Tuscaloosa, AL 35487-0205.