Effects of granular soil micro-mechanics on the pressure-sinkage relationship

The pressure-sinkage relationship is a common and important issue in terrain mechanics to explore the soil-vehicle interaction for the off-road vehicles. There are a number of empirical pressure-sinkage relationships available, which were established by curve fitting to experimental data. However, not much research has been performed to establish the link between the micro-mechanics of soil and the pressure-sinkage relationship, e.g. the effect of soil density, inter-particle friction, particle rolling resistance, and different gravity. In this paper, the effects of micro-mechanical parameters of soil on the pressure-sinkage relationship were investigated using the Discrete Element Method (DEM). The pressure-sinkage relationship from the DEM simulations matched the result from the experimental tests on coarse sand. It has been found that the sinkage is quite sensitive to the inter-particle friction (particle surface roughness), but is not particularly sensitive to the soil-vehicle friction, which indicate...