Preliminary assessment of the factors controlling the geotechnical and hydrological properties in the hillslope deposits of Eastern Tuscany (Central Italy)

The main aim of this study is to determine the geotechnical properties of hillslopes of Eastern Tuscany (Central Italy), by means of a campaign of in situ measurements and laboratory experiments. The study shows that the analysed materials are mainly composed by sand and silt, with highly variable content of gravel and clay. This grain size distribution is not strictly dependent on bedrock type. As a consequence, shear strength and hydraulic conductivity are difficult to predict only on the base of the lithotechnical classification of bedrock. In addition to grain size, the different vegetation cover types affect the in situ geotechnical and hydrological parameters, but this contribution is still difficult to be quantitatively assessed. Data retrieved are considered beneficial in order to improve the reliability of numerical model aimed to simulate the stability of hillslopes and assess triggering mechanisms for landslides.