1. Professor and Regents’ Lecturer, Dept. of Civil Engineering, Univ. of New Mexico, MSC01-1070, Albuquerque, NM 87131-0001.
2. Graduate Research Assistant, Dept. of Civil, Architectural and Environmental Engineering, Univ. of Texas at Austin, Ernest Cockrell Jr. Hall, 301 E. Dean Keeton St., Stop C1700, Austin, TX 78712-1056.
3. Assistant Professor, Dept. of Civil Engineering, Univ. of Bahrain, Bldg. 28 UOB, Isa Town, Kingdom of Bahrain 734 (corresponding author).