1. Geotechnical Engineer, Coffey Geotechnics, Sydney, Australia; and Ph.D. Candidate, Dept. of Civil, Mining and Environmental Engineering, Univ. of Wollongong, Northfields Ave., Wollongong, New South Wales 2522, Australia (corresponding author).
2. Professor, Dept. of Civil, Mining and Environmental Engineering, Univ. of Wollongong, Northfields Ave., Wollongong, New South Wales 2522, Australia.