1. Dept. of Civil Engineering, Univ. of Aveiro, Campus Universitario de Santiago, 3810-193 Aveiro, Portugal (corresponding author).
2. Hydraulic Steel Structures Division, ATB Riva Calzoni Spa, Via Industriale 13, 25030 Roncadelle (BS), Italy; formerly, Dept. of Water Engineering and Chemistry, Technical Univ. of Bari, Bari, Italy.
3. Dept. of Civil Engineering and Architecture, IST, Technical Univ. of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon, Portugal.
4. Dept. of Civil and Environmental Engineering, Univ. of California, Davis, 2001 Ghausi Hall, One Shields Ave., Davis, CA 95616.