1. Research Associate, Dept. of Civil and Environmental Engineering, Geotechnical Research Center, Univ. of Western Ontario, London, ON, Canada N6A 5B9; Dept. of Civil Engineering, Univ. of Benghazi, P.O. Box 1308, Benghazi, Libya (corresponding author).
2. Professor, Dept. of Civil and Environmental Engineering, Geotechnical Research Center, Univ. of Western Ontario, London, ON, Canada N6A 5B9.
3. Associate Professor, Dept. of Civil and Environmental Engineering, Geotechnical Research Center, Univ. of Western Ontario, London, ON, Canada N6A 5B9.