1. Research Fellow, Dept. of Civil and Environmental Engineering, Univ. of Auckland, Private Bag 92019, Auckland 1010, New Zealand (corresponding author).
2. Student Researcher, Dept. of Civil and Environmental Engineering, Univ. of Auckland, Private Bag 92019, Auckland 1010, New Zealand.
3. Professor, School of Civil, Environmental and Mining Engineering, Univ. of Adelaide, Adelaide 5005, Australia.
4. Professor, Dept. of Civil and Environmental Engineering, Univ. of Auckland, Private Bag 92019, Auckland 1010, New Zealand.