Cyclic response of stereoscopic geogrid–sand interface under static and cyclic loading

Abstract

The investigation of cyclic shear response on a geosynthetic–soil interface is important for reinforced soil structures. A stereoscopic geogrid with a thickened transverse-rib thickness increases the interaction with the soil compared with a planar geogrid. In this study, three-dimensional printing technology was used to produce stereoscopic geogrids with transverse-rib thicknesses of 5, 10, 15 and 20 mm. The influences of different cyclic shear displacement amplitudes (1, 3, 6 and 10 mm) and normal stresses (20, 40 and 60 kPa) on the direct shear tests under static and cyclic loading at the stereoscopic geogrid–sand interface were investigated. The results indicate that the maximum shear stress can be improved by the stereoscopic geogrid at larger cyclic shear displacement amplitudes. The effect of transverse-rib thickness on the fitted curves of the normalised interface shear stiffness and damping ratio was reversed. The cyclic shear process altered the relationship between apparent cohesiveness and transverse-rib thickness. The peak stress ratio of the stereoscopic geogrid–sand interface is proposed as a function of the transverse-rib thickness and maximum dilation angle.