Repeated Load Testing of a Granular Material

Both the resilient and permanent strains were measured and shown to reach equilibrium values after some 10⁴ stress cycles under drained test conditions. The effect of changes in both the mean level and the amplitude of the deviator stress were studied and samples were tested at various constant cell pressures. The measured strains were shown to be dependent on the applied stress conditions expressed as dynamic deviator stress, mean normal stress, and cell pressure. The well-known nonlinearity between stress and resilient strain was noted and quantified for this particular material. The simple relationship previously established between resilient modulus and either cell pressure or the sum of the principal stresses was investigated and found to apply only under specific circumstances. More generally, resilient modulus depended on both the normal and shear stress conditions.