Experimental study on particle breakage of gravel-geogrid interfaces under cyclic shear

In order to analyze the particle breakage of gravel-geogrid interfaces under cyclic shearing, cyclic direct shear tests of gravel geogrid interfaces were performed under different cyclic shear displacement amplitudes, normal stresses, shear frequencies and cycle numbers. The particle distribution change before and after cyclic shearing was analyzed, and the particle breakage was quantified by the relative particle breakage ratio. The test results show that the peak shear stress of each hysteresis loop increases gradually as the number of cycles increases, and fluctuates due to particle breakage. The relative particle breakage ratio increases with increasing the amplitude of the cyclic shearing displacement, obeying a hyperbolic function relationship. A logarithmic function can be used to describe the relationships between the normal stress and the shear frequency with the relative breakage ratio. The maximum relative breakage ratios are 13.54% and 11.22% for different normal stresses and shear frequencies. The number of cycles has a significant influence on the relative particle breakage ratio, and the larger the cycle number, the larger the relative breakage ratio. Moreover, under different test conditions, the relative particle breakage ratio has a non-linear positive correlation with the input plastic work, and the relationship between them can be described by a hyperbolic function. © 2021, Science Press. All right reserved.