Dynamic photogrammetric survey of moving granular masses at laboratory scale.

The experimental research is aimed at the description, with photogrammetric techniques, of the evolution of the surface of a moving granular mass, in order to contribute to the understanding of the rheology and to the calibration of physical-mathematical-numerical models. The experimental apparatus is constituted by two planes with adjustable inclination: an upstream plane, placed at the inclination of 27.5 °, and a downstream plane at the inclination of 6.5 °. Both planes are square- shaped with side length of 1.5 m. A fixed volume of dry granular material is released on the upstream plane and followed up to its stop on the downstream plane. two different types of granular material have been used, characterized by different size and form factor. The article describes the degree of automation achieved in the methodological approach and manual work still needed with the hardware and software techniques adopted. Finally, the experimental results are presented for some significant tests as well as the achieved metric quality.