Discrete Element Modelling of the Mechanical Behavior of Sand-Rubber Mixtures under True Triaxial Tests.

Haijun Mao,Lihua Li,Xinchao Liao,Yiming Liu

doi:10.3390/ma13245716

Abstract

Sand–rubber mixtures (SRMs) consisting of stiff sand particles and soft rubber particles are typical binary mixture materials that possess a variety of complicated properties. The complexity of the properties of sand–rubber mixtures is increased when complex stress path is involved. This study investigates the mechanical behavior of sand–rubber mixtures under generalized loading conditions using the discrete element method. A series of numerical true triaxial shear tests were conducted on pure sand and sand–rubber mixtures. The effect of rubber content and loading path on both of the macroscopic and microscopic performances of sand–rubber mixtures was investigated, and the associated microscale mechanism was also discussed. Numerical simulations show that the relationship between the peak friction angle and the intermediate principal stress ratio is influenced by the addition of rubber particles, and a suggested explanation of this phenomenon is that the rubber particles mainly affect the inherent stability of the strong network. Particle-scale observations, including the coordinate number, the proportion of strong contacts, and the fabric anisotropy, are also presented in this study. Microscopic results confirm the explanation above, and explore the force transmission characteristics of sand–rubber mixtures under generalized loading conditions. This research can provide a reference for the constitutive model development of sand–rubber mixtures.

Highlights

Sand–rubber mixtures (SRM) recently have received considerable amount of interest from both the research community and practicing engineers, and have been widely used in geotechnical engineering, including lightweight backfill, retaining walls, highway embankments, and road construction, due to its light weight, high damping, and high permeability [1,2,3,4,5,6]
Several Discrete element method (DEM) simulated true triaxial shear tests have been conducted to investigate the effect of intermediate principal stress ratio on the mechanical behavior of sand–rubber mixtures
The peak strengths of samples under conventional triaxial tests first decrease with 10% rubber numerical study are added, the following: particles and increase when the proportion of rubber particles rises up to 30%, but the strengths sand–rubber mixtures with either 10% or 30% rubber particles are lower than

Summary

Introduction

Sand–rubber mixtures (SRM) recently have received considerable amount of interest from both the research community and practicing engineers, and have been widely used in geotechnical engineering, including lightweight backfill, retaining walls, highway embankments, and road construction, due to its light weight, high damping, and high permeability [1,2,3,4,5,6]. Sand–rubber mixtures are unconventional geo-material and possess a variety of unique properties. The mechanical behavior of sand–rubber mixtures depends on the properties of host sands and on the characteristics of rubber particles. A lot of experimental and numerical research has been performed to investigate the mechanical behavior of sand–rubber mixtures. Previous results show that the mechanical behavior of sand–rubber

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Results

Conclusion