Investigation on crushing behavior and cumulative deformation prediction of slag under cyclic loading

This investigation aims to explore the crushing behavior and cumulative deformation of slag under cyclic loading by both cyclic triaxial simulation tests through PFC5.03D and in-situ vibration tests. The particle crushing index Kg was proposed to characterize the evolution of particle crushing of slag. The negative exponential MechanicsEmpirical model (M-E) was summarized to predict the cumulative deformation of slag and validated by in-situ vibration tests. Three crushing types for slag particles are observed: rupture, breakage, and surface grind, respectively. The Kg increases with increasing confining pressure, frequency, and cyclic deviatoric stress. The Kg exhibits a linear correlation with the accumulated strain under the same confining pressure, and the confining pressure would inhibit the accumulated strain. The rebound modulus of slag decreases with the dynamic strain. The normal contact force mainly exists in the vertical direction under various loading settings, and the maximum rotates toward the axial direction with the increasing cyclic deviatoric stress. The trend of the settlement predicted by the M-E model is similar to that of the measured by the vibration test, but the prediction is more conservative on the safe side than that measurement.