1. Professor, School of Civil, Mining and Environmental Engineering, Univ. of Wollongong, NSW 2522, Australia (corresponding author).
2. Ph.D. Student, School of Civil, Mining and Environmental Engineering, Univ. of Wollongong, NSW 2522, Australia.
3. Lecturer, School of Civil, Mining and Environmental Engineering, Univ. of Wollongong, NSW 2522, Australia.