Validation the applicability of the Type II generalized scaling law using DEM simulations

Abstract

To validate the generalized scaling law (GSL) from both macroscopic and microscopic scales, and investigate the validity of Rocha's assumption under both drained and undrained condition, the monotonic drained and undrained triaxial tests of granular assembly were performed by using discrete element method (DEM) simulations. The tests were performed with initial confining pressures of 50 kPa, 100 kPa, 200 kPa and 500 kPa, where the specimens of 500 kPa were considered as the prototype and the others treated as the model. The results of the drained triaxial tests show that, if a normalized strain is introduced, the stress-strain relationship and the evolution of microscopic parameter a_c could be normalized before the peak, which implies that the Rocha's assumption holds true at both macroscopic and microscopic scales before the peak. However, the normalized strain is smaller than that recommended by the Type II GSL. The undrained test results indicate that the stress-strain curve could be normalized before phase transformation state, while could not be normalized due to the difference of initial mechanical average coordination number between the model and the prototype after phase transformation state.