1. Associate Professor, Dept. of Civil and Environmental Engineering, Univ. of Brasília, Brasília, DF 70910-900, Brazil (corresponding author).
2. Associate Professor, Dept. of Civil and Environmental Engineering, Univ. of Brasília, Brasília, DF 70910-900, Brazil.
3. Professor, Dept. of Civil and Environmental Engineering, Univ. of Brasília, Brasília, DF 70910-900, Brazil.