Classification, overconsolidation and stiffness of Venice lagoon soils from CPTU.

This paper reports the latest results of a field study based on a consistent set of piezocone tests (CPTU) performed at the Treporti Test Site (Venice, Italy) within an extensive research project aimed at better understanding the heterogeneous Venetian lagoon subsoil, mainly composed of silts combined with sands or clays. The project also included the construction and the subsequent gradual removal of a full scale test bank, together with a detailed monitoring system of subsoil strains and pore water pressures. This study especially focuses on the evaluation of overconsolidation and loading-unloading stiffness of such complex silty sediments from the interpretation of CPTU measurements and discusses the effectiveness of some existing and well-established approaches for classification and mechanical characterization of Venetian soils. Site specific correlations, calibrated on field measurements, are proposed in order to properly estimate typical soil parameters.