1. Assistant Professor, Dept. of Structural Engineering, Univ. of Naples Federico II, Via Claudio 21, Naples I-80125, Italy (corresponding author).
2. Associate Professor, Dept. of Geotechnical Engineering, Univ. of Naples Federico II, Via Claudio 21, Naples I-80125, Italy.
3. Full Professor, Dept. of Structural Engineering, Univ. of Naples Federico II, Via Claudio 21, Naples I-80125, Italy.