1. Dept. of Civil and Environmental Engineering, Washington State Univ., P.O. Box 645815 Pullman, WA 99164-5815.
2. Civil Engineering Dept., Federal Univ. of Rio Grande do Sul, Av. Osvaldo Aranha, 99, 3º andar, 90035 - 190 Porto Alegre/RS – Brazil.
3. Laboratory for Testing and Modeling Structures, Federal Univ. of Rio Grande do Sul, Av. Bento Gonçalves, 9500 – Prédio 43436, 91509-900 Porto Alegre/RS – Brazil.