1. Department of Civil Engineering, University of Calgary, Calgary, Alberta AB T2N 1N4, Canada.
2. PB Consult, Inc., 400 Southwest Sixth Avenue, Suite 802, Portland, OR 97204-1412.
3. PB Consult, Inc., 6100 Uptown Boulevard NE, Suite 700, Albuquerque, NM 87110-4174.