1. Graduate Student, Dept. of Civil and Environmental Engineering, The Univ. of Auckland, Private Bag 92019, Auckland, New Zealand (corresponding author).
2. Professor, Dept. of Civil and Environmental Engineering, The Univ. of Auckland, Private Bag 92019, Auckland, New Zealand.
3. Senior Lecturer, Dept. of Civil and Environmental Engineering, The Univ. of Auckland, Private Bag 92019, Auckland, New Zealand.