1. Full Professor, Dept. of Structural Engineering and Geotechnics, Sapienza, Univ. of Rome, via A. Gramsci 53, 00197 Rome, Italy.
2. Ph.D. Student, Dept. of Structural Engineering and Geotechnics, Sapienza, Univ. of Rome, via A. Gramsci 53, 00197 Rome, Italy.
3. Assistant Professor, Dept. of Environmental Engineering and Sustainable Development, Technical Univ. of Bari, viale del Turismo 10, 74100 Taranto, Italy (corresponding author).