Effects of freeze-thaw cycles on the tensile properties of geogrids and shear behavior of geogrid-soil interface

Abstract

Abstract The tensile strength of geogrids and the shear strength of the reinforced soil interface are critical technical indicators for designing reinforced soil structures. This study developed a temperature-controlled apparatus to examine the tensile properties of geogrids subjected to freeze-thaw cycles within the soil, and the effect of interface temperature and freeze-thaw cycles on the shear behavior of the geogrid-soil interface. Eight and four groups of direct shear and tensile tests were conducted on the geogrid-soil interface and geogrids, respectively, under varying conditions. The peak tensile strength of geogrids remained similar to that of non-freeze-thaw samples after experiencing freeze–thaw cycles within the soil. tensile properties of geogrids were independent of the number of freeze–thaw cycles. At constant water content (w=6%), the peak shear stress at the geogrid-soil interface decreased by 24% (7 freeze-thaw cycles) compared to the non-freeze-thaw group. The cohesion and friction angle of the geogrid-soil interface decreased with increasing freeze-thaw cycles but tended to stabilize after 4 freeze-thaw cycles. The reinforcement provided by the geogrid enhanced with decrease in the interface temperature. The shear stress was higher at interface temperature under 0 °C, whereas in a non-frozen state, the interface exhibited lower shear stress with a consistent stable value.