Interpretation of Geomaterial Behavior during Shearing Aided by PIV Technology

Several researchers have studied the behavior of particles during shearing to have better insight into the Mohr-Coulomb (MC) strength parameters. In most cases, the movements of particles along the shear band were studied by means of numerical modeling to obtain the velocities and directions of the soil particles. The use of a transparent shear box highlights the original enhancement and contribution in this paper to study the mechanical behavior of particles using particle image velocimetry (PIV) along the shear zone. Previous research using a transparent shear box suffered from several limitations such as obstructed view of the shear zone or using numerical simulation. The tested specimens consisted of sand and reconstituted rock spoils of metagreywacke and shale origins, which were classified according to their shapes and mineralogy contents. Particle shearing behavior was analyzed in detail at various stages throughout the direct shear tests with results complementing the PIV assessments. This novel interpretation technique successfully demonstrated how particle shapes and angularity, mineralogy, and effects of particle dilation and compression under shear can influence the strength parameters.