1. Professor, Dept. of Civil Engineering, Univ. of New Mexico, Albuquerque, NM 87131 (corresponding author).
2. Project Engineer, Golder Associates Inc., 44 Union Blvd., Suite 300, Lakewood, CO 80228.
3. Associate Professor, Dept. of Civil Engineering, Univ. of New Mexico, Albuquerque, NM 87131.