1. Professor of Civil Engineering, Faculty of Engineering, Univ. of Wollongong, Wollongong City, New South Wales 2522, Australia (corresponding author).
2. Research Associate, Faculty of Engineering, Univ. of Wollongong, Wollongong City, New South Wales 2522, Australia.
3. Senior Geotechnical Adviser, RailCorp, New South Wales 2777, Australia.
4. Senior Lecturer, Faculty of Engineering, Univ. of Wollongong, Wollongong City, New South Wales 2522, Australia.
5. Lecturer, Faculty of Engineering, Univ. of Wollongong, Wollongong City, New South Wales 2522, Australia.