Instability behavior of loose granular material: a new perspective via DEM

The effects of the stress loading rate and maximum servo wall speed on the instability characteristics of granular materials were investigated using stress-controlled biaxial compression simulation. The results indicate that: (1) the stress loading rate affects the destabilization process of the specimen, with a higher stress loading rate making it easier for the sample to destabilize in a shorter time. (2) The maximum servo wall speed impacts the shear behavior of the specimen and can even lead to simulation test failure. It is therefore strongly recommended that this parameter be listed as a key parameter in future studies. (3) Based on the above analysis, a new conceptual framework was proposed to characterise the different cases of stress-controlled tests, which can guide the rational selection of rates.