1. Ph.D. Candidate, Dept. of Civil Engineering, Federal Univ. of São Carlos, Rodovia Washington Luiz km 235, São Carlos, 13565-905 São Paulo, Brazil.
2. Professor, Dept. of Civil Engineering, Federal Univ. of São Carlos, Rodovia Washington Luiz km 235, São Carlos, 13565-905 São Paulo, Brazil.
3. Associate Professor, Dept. of Civil and Environmental Engineering, Brigham Young Univ., 368 Clyde Building, Provo, UT 84602 (corresponding author).