Bearing characteristics of reinforced soil with longitudinal and transverse ribs of geogrids

In order to study the stress characteristics of interface between longitudinal and transverse ribs of geogrids and sand, the pullout tests are carried out under different normal pressures. Six pull-out test conditions are designed by trimming ribs in the transverse and longitudinal directions. The effects of geogrid stress, pullout resistance peak and displacement and apparent friction coefficient are studied owing to reduction of transverse ribs, and the pullout resistances under two modes of general shear failure and punching shear failure are compared, which reveales the interaction mechanism of reinforced soil interface. The results show that with the decrease of the transverse ribs, the pullout resistance and apparent friction coefficient of geogrids are decreased. The maximum pullout resistance of geogrids that the ribs are reduced in the transverse direction is larger than that of the ribs reduced in the longitudinal direction. The full transverse ribs can contribute to the reinforcement effect of the interface. The skin friction component of theoretical calculation is about 18%~19% of the experimental pullout resistance, while the experimental skin friction component is about 29% -33% of the experimental pullout resistance, and the bearing capacity component of the transverse ribs accounts for 67%~71% of the total pullout resistance. The transverse ribs greatly improve the pullout resistance of geogrids.