Three dimensional discrete element method simulations of interface shear

Abstract

Granular-continuum interfaces are widely present in geotechnical applications, including deep foundations, retaining structures, and anchoring applications. Interface mechanical properties are a function of the characteristics of the contacting soil and the opposing interface. Therefore, a robust understanding of granular-continuum interface behavior is essential to geotechnical practice. In this work, we did the following: (1) summarized the recent research on the effects of interface roughness, soil density, particle shape, and friction coefficient on interface behavior and strength; (2) simulated granular-continuum interface shear using the three-dimensional discrete element method (DEM); (3) compared the trends in DEM results to previously published physical experiments; and (4) investigated the microscale responses of the interface simulations. The DEM simulations were generally in good agreement with previously reported experimental results for similar interface roughness. DEM simulations give a bilinear strength-displacement trend consistent with that previously reported from physical experiments. The microscale investigations showed that, in the case of rougher interfaces, contact reorientation was the interface failure mechanism, and in the case of smoother interfaces, it was contact sliding. The mobilization of rougher interfaces tends to alter the force distribution in the surrounding soil.