1. Senior Research Associate, School of Civil and Environmental Engineering, Univ. of Adelaide, SA 5005, Australia. E-mail: mmsadakk@civeng.adelaide.edu.au
2. Professor, School of Civil and Environmental Engineering, Univ. of Adelaide, SA 5005, Australia. E-mail: doehlers@civeng.adelaide.edu.au
3. Associate Professor and Head, School of Civil and Environmental Engineering, Univ. of Adelaide, SA 5005, Australia. E-mail: mcgrif@civeng.adelaide.edu.au