1. Associate Professor, Dept. of Civil Engineering, Federal Univ. of Rio Grande do Sul, Av. Osvaldo Aranha, 99, 3 andar, CEP 90035-190, Porto Alegre, Rio Grande do Sul, Brazil.
2. Ph.D. Student, Dept. of Civil Engineering, Federal Univ. of Rio Grande do Sul, Av. Osvaldo Aranha, 99, 3 andar, CEP 90035-190, Porto Alegre, Rio Grande do Sul, Brazil.
3. Research Assistant, Dept. of Civil Engineering, Federal Univ. of Rio Grande do Sul, Av. Osvaldo Aranha, 99, 3 andar, CEP 90035-190, Porto Alegre, Rio Grande do Sul, Brazil.