DEM study on the impact mechanical properties and failure characteristics of frozen soil under coupled compression–shear loading

Abstract

It is important to study the effects of the mechanical properties and failure characteristics of defective frozen soil under coupled compression–shear loading for engineering construction safety and disaster prevention. In this study, the particle flow code was used to establish the distinct element method (DEM) model of a split-Hopkinson pressure bar experiment on frozen soil. The failure processes of frozen soils with different tilting angles and holes were simulated using the DEM model to investigate the influence of the tilting angle and hole deviation (deviation from the geometric center of the frozen soil specimen) on the impact mechanical properties and failure characteristics of frozen soil specimens under coupled compression–shear loading. The results of numerical simulation indicated that when the tilting angle and impact strain rate were 0° and 100 s⁻¹, the axial peak stress of frozen soil specimen with a hole was smaller than that without a hole, the hole deviation had a minor influence on the axial peak stress. When the strain rate was 100 s⁻¹, the axial and shear peak stresses of the frozen soil specimen without a hole increased and decreased, respectively, with increasing tilting angle, and the number proportion of shear-cracks also increased. When the tilting angle and strain rate were 60° and 100 s⁻¹, the fully deviated hole had a minor influence on the impact mechanical properties and failure characteristics of the frozen soil. The impact loading also had a minor influence on the deformation of the hole.