1. Associate Professor of Geotechnics, Dept. of Civil and Informatics Engineering, Univ. of Rome Tor Vergata, Via del Politecnico No. 1, Rome 00133, Italy (corresponding author).
2. Ph.D. Student, Dept. of Civil and Informatics Engineering, Univ. of Rome Tor Vergata, Via del Politecnico No. 1, Rome 00133, Italy.