1. Ph.D. Fellow, IST–Univ. of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon, Portugal.
2. Full Professor, Dept. of Civil Engineering, Architecture and Georesources, IST–Univ. of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon, Portugal (corresponding author).
3. Full Professor, Faculty of Engineering of the Univ. of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal.
4. Assistant Professor, IST–Univ. of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon, Portugal.