Time-Dependent Behaviour and Ageing of Sands – Single Grain Analysis

Abstract For more than four decades, it has been observed that changes with time in the engineering properties of soils, such as stiffness, strength, dilatancy, among others, are the result of ageing [1]. Despite several proposed hypotheses, a satisfactory explanation for soil ageing remains elusive. Notably, particle packing rearrangement plays a central role, influenced by grain crushing under high load and softening, rolling, and sliding of grains under low load. The discrete element method (DEM) along with the parallel stress-corrosion (PSC) model developed by Potyondy [2] are employed to model the time-dependent behaviour of granular materials. Through a series of static-fatigue compression tests on single grains, critical data—such as axial load and displacement, time-to-failure and static fatigue limit —is meticulously recorded. The simulation results underscore the significant impact of loading history on induced grain damage and its time-dependent behaviour.