Dynamic Impact Experiment and Numerical Simulation of Frozen Soil with Prefabricated Holes

Abstract

To explore the effects of holes and other defects on the dynamic mechanical properties of frozen soil under impact loading, frozen soil samples with three types of circular hole defects and different apertures were developed, and a dynamic compression experiment was performed with a split Hopkinson pressure bar (SHPB) device. The results indicated that the existence of holes weakens the dynamic compressive properties of frozen soil. The effects of temperature and holes on the defective samples were evident. The trend observed in the stress–strain curve was consistent with that observed in the samples without holes. The SHPB experiment using frozen soil samples with prefabricated holes was numerically simulated using LS-DYNA software and the Holmquist–Johnson–Cook material model; the simulation results showed good agreement with the experimental results. Using the postprocessing software LS-Prepost, the specific failure mode of the samples with holes was identified. The samples were found to have an X-type shear failure that was consistent with the theoretical research and the same as the failure rule of rock with holes. The dissipation energy per-unit volume was used to represent the energy-dissipation efficiency of the sample in the experiment. As the failure of a sample with holes led to more cracks, the energy-dissipation rate of a sample with holes was higher than that of a sample without holes, and it increased as the aperture increased.