Evolution of granular media under constant-volume multidirectional cyclic shearing

By means of the three-dimensional discrete element method, we study long-time evolution toward liquefaction state in granular materials composed spherical particles under multidirectional cyclic shearing at constant volume. Extensive simulations were carried out along 1-D linear, 2-D circular/oval, and 8-like shear paths, system was analyzed terms pore pressure, strain, texture. The macroscopic stress path stress–strain response agree well with laboratory experiments. We find that resistance, i.e., number cycles necessary to reach state, is generally lower loading as compared unidirectional loading. As transient vanishing mean does not occur for all introduce a strain-based criterion can be consistently applied strain paths. texture monitored through coordination number, particle connectivity, force fabric anisotropies, friction mobilization. In particular, particle-void descriptor, named centroid distance, found closely related accumulation. show anisotropy tensors become almost proportional deviatoric tensor more quickly than tensor, which takes most pre-liquefaction period follow external relationship between ratio known hold monotonic triaxial loading, also holds high accuracy studied paths; contributing weights anisotropies level off post-liquefaction do depend on path.