1. Research Fellow, School of Built Environment, Curtin Univ., GPO Box U1987, Perth, WA 6845, Australia (corresponding author).
2. Lecturer, Dept. of Construction Management, Curtin Univ., GPO Box U1987, Perth, WA 6845, Australia.
3. Associate Professor, Dept. of Civil Engineering, Univ. Técnica Federico Santa María, Valparaiso 1680, Chile.