1. Professor, Dept. of Civil and Materials Engineering, Univ. of Illinois at Chicago, 842 West Taylor St., Chicago, IL 60607 (corresponding author).
2. Lecturer, Dept. of Civil and Environmental Engineering, Univ. of Alabama in Huntsville, 301 Sparkman Dr., Huntsville, AL 35899.
3. Graduate Research Assistant, Dept. of Civil and Materials Engineering, Univ. of Illinois at Chicago, 842 West Taylor St., Chicago, IL 60607.