A Multi-Scale Drucker–Prager Strength Criterion Based on Microscopic Physical Soil Analysis

The coupling of interactions between liquid, gas and particles in soil at different scales leads to specific particulate and structural soil characteristics. In this study, a soil cell element model was used to establish a multiscale Drucker–Prager strength criterion with respect to the microscopic physical details of soil. A series of soil cell element samples were prepared for consolidated and undrained triaxial compression tests that were used to calculate the model parameters. Using theoretical analysis and experimental results, the yield locus of the multiscale Drucker–Prager strength criterion was drawn on a deviatoric plan. The results showed that the yield locus was consistent with the experiments, and became larger as the reinforcement particle size decreased and the particle volume fraction increased. Therefore, the multi-scale Drucker–Prager strength criterion relates the microscopic physical soil characteristics to its macroscopic strength.