1. Professor Dean, Engineering Faculty of Taranto, Dept. of Civil and Environmental Engineering, Technical Univ. of Bari, via le del Turismo, 8, 74100 Taranto, Italy (corresponding author).
2. Research Fellow, Dept. of Civil and Environmental Engineering, Technical Univ. of Bari, v. E. Orabona 4, 70123 Bari, Italy.
3. Visiting Research Fellow, Engineering Faculty of Taranto, v. le del Turismo 8, Technical Univ. of Bari, 74100 Taranto, Italy.