High resolution sedimentological and geotechnical characterization of the Late Quaternary deposits in the Italian central Adriatic coast (Tronto River mouth)

Abstract

In order to investigate the effective role of sedimentological analysis in the interpretation of geotechnical data, with special reference to coastal transitional paleoenvironments, a study on the Quaternary alluvial and coastal plain successions forming the upper 30m of the Tronto River valley subsoil, facing the Italian Central Adriatic Sea, has been carried out.According to the analysis of a continuously-cored borehole and a few adjacent piezocone tests, four depositional facies have been recognized from last deglaciation to present, reflecting the changes in sedimentation due to sea-level changes and local erosion-subsidence phenomena. Furthermore, three 14C dates have provided the basis to establish the chronological framework of the succession. The interpretation of piezocone data has allowed an accurate geotechnical characterization of the different soil units, also accounting for their sedimentological environment. Specific issues concerning the mechanical response and the determination of soil parameters of facies, with special reference to the heterogeneous sedimentary formation known as flaser bedding, have been discussed and appropriate piezocone-based interpretation procedures have been identified. The final aim of this combined geo-sedimentological and geotechnical study is to propose a possible methodological approach in which both analyses can contribute to a better understanding of local subsoil for territorial planning and related engineering applications.