1. Ph.D. Student, Dept. of Civil and Environmental Engineering, Univ. of Auckland, Auckland 1023, New Zealand (corresponding author).
2. Assistant Professor, Dept. of Civil and Environmental Engineering, Washington State Univ., Pullman, WA 99164.
3. Professor, Dept. of Civil and Environmental Engineering, Univ. of Auckland, Auckland 1023, New Zealand.
4. Senior Lecturer, Dept. of Civil and Environmental Engineering, Univ. of Auckland, Auckland 1023, New Zealand.
5. Professor, Dept. of Civil and Environmental Engineering, Univ. of Washington, Seattle, WA 98195-2700.