1. Dept. of Civil Engineering, Curtin Univ., Bentley, Perth, WA 6102, Australia. ORCID: .
2. Dept. of Civil Engineering, Curtin Univ., Bentley, Perth, WA 6102, Australia; formerly Dept. of Mathematics & Statistics, Univ. of Melbourne, VIC 3010, Australia (corresponding author). ORCID: .
3. Dept. of Mathematics & Statistics, Univ. of Melbourne, VIC 3010, Australia. ORCID: .