An automated procedure for computing the packing properties of dense and locked sands by image analysis of thin sections

The macroscopic mechanical behaviour of dense sands originates to a great extent from their microstructural characteristics such as the coordination number, the grain contact and the packing density indexes. The study of intergranular contacts and the reckoning of these indexes may be carried out on planar images of the grains either by means of time-consuming visual inspection assisted by CAD or by automatic image analysis. An innovative method for the automatic determination of microstructural characteristics of sands based on image analysis of thin section is proposed. Tests performed on a locked sand show that the proposed method is much more effective, convenient and faster than the usual visual inspection technique. Therefore, it can be considered an extremely useful tool for calibrating predictive models for arrangements of granular media based on computer simulations.