Deformation Behavior of Coarse-Grained Soil as an Embankment Filler under Cyclic Loading

Zhong-Ming He,Qian-Feng Gao,Han-Bing Bian,Ya-Xin Liu,Da Xiang

doi:10.1155/2020/4629105

Zhong-Ming He, Qian-Feng Gao + Show 3 more

Open Access

https://doi.org/10.1155/2020/4629105

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Abstract

This study aims to examine the deformation behavior and internal mechanism of coarse-grained soil as an embankment filler under cyclic loading. Numerical dynamic triaxial tests were performed on coarse-grained soil using the discrete element software PFC3D. The numerical model was verified by comparing the numerical results with the experimental data. Afterward, the changes in the porosity, force chain, and particle movement of coarse-grained soil samples were analyzed, and the mesoscopic deformation behavior of coarse-grained soil under cyclic loading was investigated. The research results show that with the increase of the deviatoric stress amplitude, moisture content, and loading frequency, the deformation of the soil increases and the ability to resist deformation decreases at the same loading cycles. Due to the inhomogeneous distribution of particles with different sizes, the velocity and displacement of the sample vary in different directions, exhibiting mesoscopic anisotropy. The contact force is relatively even in the downward direction while dispersed near the edge of the sample. This means that the particles at the bottom are less affected by loads and the internal evolution of soil samples conforms to its macroscopic deformation behavior during cyclic loading.

Highlights

Coarse-grained soil refers to the soil in which the grains are between 0.075 mm and 60 mm accounting for more than 50% of its total mass [1]
To control the deformation and stability of the coarse-grained soil embankment, it is necessary to have a better understanding of the deformation behavior of coarse-grained soil during cyclic loading
Wang et al [4, 5] investigated the resilient modulus, damping ratio, and permanent deformation of coarse-grained soil by monotonic and cyclic triaxial tests. e behavior of coarse-grained soil was studied based on the continuous medium assumption

Summary

Introduction

Coarse-grained soil refers to the soil in which the grains are between 0.075 mm and 60 mm accounting for more than 50% of its total mass [1]. Jiang et al [12, 13], Hu et al [14], and Shen et al [15] examined the effects of different confining pressures, porosity, and particle rotations on the mechanical properties of granular materials using both laboratory triaxial tests and DEM simulations. E research mentioned above focused on the mechanical properties and deformation behavior of different granular materials under various static or cyclic loads but dealt less with the dynamic behavior of coarse-grained soil subjected to vehicle loads. E changes in the porosity, force chain, and particle movement of coarse-grained soil samples are examined, and the mesoscopic deformation behavior of coarse-grained soil under cyclic loading is analyzed.

Numerical Dynamic Triaxial Tests

Experimental results

Analysis of Calculation Results

Conclusion