1. Ph.D. Candidate, Dept. of Civil and Environmental Engineering, Univ. of Auckland, Auckland 1010, New Zealand (corresponding author).
2. Senior Lecturer (Transportation), Dept. of Civil and Environmental Engineering, Univ. of Auckland, Auckland 1010, New Zealand.
3. Senior Lecturer (Geomechanics), Dept. of Civil and Environmental Engineering, Univ. of Auckland, Auckland 1010, New Zealand.
4. Professor Emeritus (Geology), School of Environment, Univ. of Auckland, Auckland 1010, New Zealand.