ABSTRACT
The paper presents an innovative laboratory technique aimed at determining the viscous proprieties of soil-water mixture involved in fast landslides. The knowledge of their rheological properties are necessary for assessing the spreading areas that may danger and damage persons and properties (hazard mitigation). The new equipment is a drag ball rheometer, called Sphere Drag Rheometer (SDR). Compared to standard rheometer this system uses much higher volume of mixtures of wider grain size distribution. The calibration procedure are illustrated with reference to Newtonian and Non-Newtonian standard fluids. The flow curve of some pyroclastic soil-water mixtures are presented. The experimental results on fine mixture are compared with those obtained by conventional rheometrical tools. The results show that the SDR rheometer is able to evaluate the rheological properties of soil-water mixture similar to those involved into pyroclastic debris flow.
