Examination of interface roughness and particle morphology on granular soil–structure shearing behavior using DEM and 3D printing

Abstract

Understanding the mechanical behavior of soil-structure interaction (SSI) is crucial for the safety and stability of infrastructures. From mesoscale to macroscale, the coupled effects of particle morphology and structural surface roughness on SSI has received little attention. Herein, a series of interface shear tests and simulations were carried out by combining 3D printing and discrete element method (DEM). To quantitatively characterize particle shape and structural surface roughness, modified particle shape parameter Sh and interface morphology factor λ are introduced. The results indicate that increasing the inclination of asperities 1/λ promotes lateral slip displacement of particles and results in significant delamination at the interface. In the vertical shear direction, particle displacement exhibits two patterns: backward falling and maximum displacement at the top of the shear zone, and continuous forward displacement decrease along the height of the specimen. Thus, a new index (i.e., maximum backward falling displacement of particles) is proposed to define the shear zone thickness. Particle shapes and interface roughness have different effects on the particle displacement in the vertical shear direction. An increase in Sh reduces relative displacement, while an increase in 1/λ can increase the magnitude of the relative displacement of particle lateral sliding. The overall strength of particles depends on the coupling effect of particle shapes and interface roughness, both of which have corresponding thresholds. As the interface roughness or Sh increases, three parameters used to describe the contact state of clusters first increase until reaching a turning point and then remain stable or slightly decrease. This paper aims to broaden the understanding of the coupling effects of interfaces with various roughness and particles with different shapes on SSI, with the ultimate goal of contributing to the design of structural interfaces more effective and safety in sandy soil area.