1. a Dept. of Soil Defence , Univ. of Calabria , C.da S. Antonello, 87040 , Montalto U. Scalo , Cosenza , Italy
2. b Dept. of Hydraulic , Univ. of Padua , Maritime and Geotechnical Engineering, Via Loredan 20, 35100 , Padua , Italy
3. c Dept. of Civil Engineering , Univ. of Salerno , Via Ponte Don Melillo, 84084 , Fisciano, Salerno