1. Lecturer, School of Engineering, Univ. of Durham, South Road, Durham DH1 3LE, UK.
2. Research Academic, Dept. of Civil, Surveying, and Environmental Engineering, Univ. of Newcastle, Newcastle NSW 2308, Australia.
3. Professor, Dept. of Civil, Surveying, and Environmental Engineering, Univ. of Newcastle, Newcastle NSW 2308, Australia.