Constraint Deformation Behavior of Sand-EPS Beads Mixture Using Discrete Element Modeling (DEM)

Abstract

Lightweight composite materials are increasingly used in geotechnical engineering projects. This paper presents experimental and numerical investigations on the compressibility characteristics and “at-rest” lateral earth pressure of the mixture of expanded polystyrene (EPS) beads and some virtual steel pellets that are completely rounded particulates. The mixtures were prepared by adding EPS beads to the steel pellets at 0, 0.1, 0.2, 0.3, 0.4, and 0.5 % by weight. The experiments were carried out using two types of oedometers: the standard Casagrande and a tall oedometer apparatus. The discrete element modeling (DEM), in turn, is conducted to simulate the compressibility characteristics and “at-rest” lateral earth pressure of the EPS composite particulates using the open-source framework YADE. To this end, the mechanical parameters of different constituents are calibrated based on the direct shear experiments on the pure steel and EPS beads. Comparison of the experimental and numerical results illustrates that the DEM model can properly predict the compression and lateral earth pressure behavior of the mixtures of EPS beads and sand.

Influence of Loading History and Soil Type on the Normal Contact Behavior of Natural Sand Grain-Elastomer Composite Interfaces

“…Thus, understanding and modeling the contact behavior of composite sand–rubber interfaces is essential to be obtained through grain-scale experimental studies, which was one of the major motivations behind this work. Even though previous studies using DEM attempted to provide insights into the fundamental mechanisms that control the mechanical behavior of binary systems composed of rigid and soft grains, including sand–rubber [ 56 , 57 , 63 , 64 , 65 , 66 , 67 ], as well as sand–expanded polystyrene beads [ 51 , 68 ], there has been reported much less progress in terms of laboratory studies at the grain-scale [ 46 , 49 ]. Especially the works by Li et al [ 46 ] and He et al [ 49 ] had a major focus on the interparticle coefficient of friction and the constitutive behavior in the shearing (or tangential) direction of sand–rubber composite interfaces.…”