1. Professor, School of Civil and Environmental Engineering, Univ. of New South Wales, Sydney NSW 2052, Australia.
2. Research Engineer, School of Civil and Environmental Engineering, Univ. of New South Wales, Sydney NSW 2052, Australia.
3. Senior Geotechnical Engineering Specialist, U.S. Bureau of Reclamation, P.O. Box 25007, Denver, Colorado 80215.
4. Associate, URS Australia, 116 Miller Street, North Sydney NSW 2060, Australia.