1. Civil Engineering Dept., Univ. of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal (corresponding author).
2. Civil Engineering Dept., Univ. of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
3. Civil Engineering Dept., Univ. of Coimbra, Pólo II—Pinhal de Marrocos, 3030-290 Coimbra, Portugal.