Anisotropic Shear Strength Behavior of Soil–Geogrid Interfaces

Jun Zhang,Yafei Jia,Yewei Zheng,Ziyang Zhao,Chenxi Miao,Cheng Wang,Mingchang Ji

doi:10.3390/app112311387

Abstract

This paper presents an experimental study on the anisotropic shear strength behavior of soil–geogrid interfaces. A new type of interface shear test device was developed, and a series of soil–geogrid interface shear tests were conducted for three different biaxial geogrids and three different triaxial geogrids under the shear directions of 0°, 45° and 90°. Clean fine sand, coarse sand, and gravel were selected as the testing materials to investigate the influence of particle size. The experimental results for the interface shear strength behavior, and the influences of shear direction and particle size are presented and discussed. The results indicate that the interface shear strength under the same normal stress varies with shear direction for all the biaxial and triaxial geogrids investigated, which shows anisotropic shear strength behavior of soil–geogrid interfaces. The soil–biaxial geogrid interfaces show stronger anisotropy than that of the soil–triaxial geogrid interfaces under different shear directions. Particle size has a great influence on the anisotropy shear strength behavior of soil–geogrid interfaces.

Highlights

Geogrids have high tensile strength, and are widely used as reinforcements in pavements, embankments, slopes, retaining walls and bridge abutments [1,2,3,4,5,6]
The goal of this study is to investigate the influence of shear direction on the shear strength behavior of soil–geogrid interfaces, which could be important for the design of reinforced soil structures
For the fine sand–geogrid interfaces, taking the biaxial geogrid SS30 and the triaxial geogrid TX160 as examples, the interface shear test results for different shear directions are shown in Figures 4 and 5, respectively

Summary

Introduction

Geogrids have high tensile strength, and are widely used as reinforcements in pavements, embankments, slopes, retaining walls and bridge abutments [1,2,3,4,5,6]. The shear strength of the soil–geogrid interface plays an important role in the stability of reinforced soil structures and is key to the design of internal stability [7,8]. Extensive experimental research has been conducted to investigate the behavior of soil–geosynthetic interfaces using the pullout test and the direct shear test [9,10,11,12,13,14,15]. Research has been conducted on the influences of testing conditions on the shear strength of soil–geosynthetic interfaces, such as loading rate, cyclic loading frequency and displacement. Corresponding experimental results indicate that testing conditions have significant effects on the shear strength of soil–geosynthetic interfaces [11,27,28,29]

Objectives

Results

Conclusion