1. Researcher, Dept. of Civil Engineering, Univ. of Calabria, Ponte P. Bucci, cubo 42B, 87036 Rende, Italy.
2. Postdoctoral Fellow, Dept. of Civil Engineering, Univ. of Calabria, Ponte P. Bucci, cubo 42B, 87036 Rende, Italy (corresponding author).
3. Full Professor, Dept. of Civil Engineering, Univ. of Calabria, Ponte P. Bucci, cubo 42B, 87036 Rende, Italy.