1. Research Academic, Centre for Geotechnical and Materials Modelling, Univ. of Newcastle, NSW 2308, Australia (corresponding author).
2. Professor, Centre for Geotechnical and Materials Modelling, Univ. of Newcastle, NSW 2308, Australia.
3. Professor, Pro-Vice-Chancellor, Faculty of Engineering and Built Environment, Univ. of Newcastle, NSW 2308, Australia.
4. Research Fellow, Centre for Geotechnical and Materials Modelling, Univ. of Newcastle, NSW 2308, Australia.