1. Professor, Dept. of Civil Engineering, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 90040-060, Brazil (corresponding author).
2. Ph.D. Candidate, School of Civil, Environmental and Mining Engineering, Univ. of Western Australia, Perth, WA 6009, Australia; formerly, M.Sc. Student, Universidade Federal of Rio Grande do Sul, Porto Alegre, RS 90040-060, Brazil.
3. Ph.D. Candidate, Dept. of Civil Engineering, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 90040-060, Brazil.
4. M.Sc. Candidate, Dept. of Civil Engineering, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 90040-060, Brazil.
5. Lecturer, Dept. of Civil Engineering, Universidade do Minho, Braga, 4710-057, Portugal.
6. Lecturer, Dept. of Engineering, Universidade de Trás-os-Montes e Alto Douro, Vila Real, 5001-801, Portugal.