1. Assistant Professor, Dept. of Civil, Architectural and Environmental Engineering, Univ. of Napoli Federico II, via Claudio 21, ed. C8/A, 80125 Naples, Italy (corresponding author).
2. Associate Professor, Dept. of Civil, Architectural and Environmental Engineering, Univ. of Napoli Federico II, via Claudio 21, ed. C8/A, 80125 Naples, Italy.