Triaxial shear test apparatus showing three stages of DEM soil deformation at constant displacement or strain rate in the upper panel. A confinement stress, σ3, is imposed on the soil through a flexible membrane and an axial stress, σ1, (the deviator stress) is applied through a vertical loading ram via incremental increases in stress until failure or via a constant deformation rate. Stress versus strain for triaxial shear tests at four different confining stresses are shown in the lower panel. Volume change information (not shown) can also be determined from the DEM simulations.
Direct shear test apparatus with normal force (FN) and shear force (Fs) shown in the left image. The shear force may be applied incrementally or through a constant displacement rate. Shear stress versus shear displacement for cohesive DEM particles are shown in the right hand image for particles with surface energy of 40 J/m2. Normal and shear stresses are calculated from the area of the DEM particles in contact between the upper and lower shear box containers.
Tension strength test apparatus showing a test in progress for cohesive DEM particles (left image). The tension force (Ft) is increased incrementally or through a constant displacement rate pull. Simulation test results for DEM particles with three different particle surface energies.
A soil cone penetrometer test at two different penetration depths showing the force chains (light blue) emanating from the surface of the penetrometer tip. Penetrometer (and other in situ method) test data are often calibrated to triaxial or direct shear data to interpret penetrometer measurements.
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