ProfessorDepartment of Civil EngineeringFederal University of Rio Grande do Sul (UFRGS)99, Osvaldo Aranha Ave. #304, Porto Alegre, RS 90035-190, Brazil+55 51 3308 4485ProfessorDepartment of Civil EngineeringFederal University of Rio Grande do Sul (UFRGS)99, Osvaldo Aranha Ave. #304, Porto Alegre, RS 90035-190, Brazil+55 51 3308 4485