The IMPROVE project aims at quantitatively characterizing and modeling the behavior of geophysical granular flows with a particular emphasis on the effect of substrate properties like roughness and its interplay with the granular material grainsize on the flow characteristics. The latter include flow velocity, thickness and internal structure, which are all factors contributing to the dynamic impact that these flows can have on the territory, human beings and infrastructures.
As such, the proposed research will serve as a pillar to improve our understanding of the mobility of these flows and consequently our ability to predict the areas most likely to be inundated in geological settings where these flows occur and their impact.
Therefore, our project is embedded into the wider area of natural disaster risk management through its reduction, for which we act on the hazard quantification component.
Specifically, we want to fulfill the following objectives:
1. quantify the effect of substrate roughness on both the bulk flow properties (thickness, flow-front speed, internal fabric) and the granular flow properties vertical profiles at the wall.
2. Verify the generation of pore pressure in situations in which the granular material is not initially fluidised before it starts moving in a large-scale flume. If a pore pressure is generated, we aim at quantitatively relating this important parameter, which can significantly increase the flow propagation, to the wall and granular material properties, eg, wall roughness, particle size distribution, flow thickness. To our knowledge, it is the first time that pore pressure generation in initially not-fluidized flows is investigated at a large scale, using natural material of varying size and density and with an attempt to find a quantitative relationship between the pore pressure and the substrate and particle properties.
3. Validate and improve both complex numerical models working at the particle-wall scale and models designed to simulate the bulk flow scale that are routinely used for hazard applications; define the most appropriate rheological parameters and scaling laws for these parameters as a function of the most important physical properties.
To achieve these, two research units (RU1 led by University of Bari and RU2 led by University of Calabria) will integrate large-scale flow experiments by using and further enhancing an existing state of the art facility and numerical modeling of the experiments.