Experimental study on cyclic shear softening characteristics of gravel−geogrid interface

In order to study the softening characteristics of gravel-geogrid interface during and after cyclic shearing, a series of displacement controlled monotonic direct shear tests, cyclic direct shear tests with 2 000 cycles and post cyclic direct shear tests were carried out on the gravel-geogrid interf...

Full description

Bibliographic Details
Main Authors: LIU Fei-yu, JIANG Huai, WANG Jun
Format: Article
Language:English
Published: SCIENCE PRESS , 16 DONGHUANGCHENGGEN NORTH ST, BEIJING, PEOPLES R CHINA, 100717 2021-06-01
Series:Rock and Soil Mechanics
Subjects:
Online Access:http://rocksoilmech.whrsm.ac.cn/EN/10.16285/j.rsm.2020.6692
Description
Summary:In order to study the softening characteristics of gravel-geogrid interface during and after cyclic shearing, a series of displacement controlled monotonic direct shear tests, cyclic direct shear tests with 2 000 cycles and post cyclic direct shear tests were carried out on the gravel-geogrid interface using dynamic direct shear apparatus. The shear strength characteristics, volume change behavior, shear stiffness and damping ratio of the gravel-geogrid interface under four groups of normal stresses of 20, 40, 60 and 80 kPa were studied. The direct shear characteristics of the gravel-geogrid interface before and after cyclic shear were compared and analyzed. The results show that: in the cyclic direct shear test, the average peak shear stress of gravel-geogrid interface first increases and then decreases, and finally tends to be stable with the increase of number of cycles, and the interface shows shear softening characteristics; the vertical displacement increment of gravel-geogrid interface decreases gradually with the increase of number of cycles; the shear stiffness first increases and then decreases with the increase of number of cycles, and finally tends to be stable; the damping ratio first decreases and then increases with the increase of number of cycles, and finally tends to be stable; under the same normal stress, the peak shear stress increases and the residual shear stress decreases in the cyclic direct shear test compared with the monotonic direct shear test; the cyclic shear makes the interface cohesion increase significantly and the internal friction angle decrease.
ISSN:1000-7598