Effect of temperature on geogrid-soil interface performance based on pullout test

The geosynthetic–soil interface interaction mechanism under changes in ambient temperature may influence the serviceability of geosynthetic–reinforced soil (GRS) structures. However, very few studies analysed the effect of temperature on interface behaviour. This study conducted 20 pullout tests to investigate the effects of interface temperature and normal stress on the geogrid–sand interaction. The test results demonstrated that the interface temperature significantly affects the pullout performance. At lower interface temperatures, the peak pullout forces at the interfaces under the same normal stress are higher, whereas the time to reach the peak pullout force is longer at higher interface temperatures. The lag effect in the tensile force transfer along the reinforcement length becomes more prominent as the interface temperature increases, and both the geogrid displacement and average strains farther from the loading end decrease significantly. Additionally, the interface shear strength decreases as the interface temperature increases. In this paper, two reduction factors involving the interfacial cohesion and friction angle are presented, and the relationship between each reduction factor and interface temperature is established. The results provide valuable insights into the design of GRS walls subjected to varying environmental temperatures.