Abstract: Geogrid is an important way to improve the bearing capacity of rubber gravel mixture. The dynamic characteristics and mechanism of geogrid-reinforced rubber gravel composites were investigated through large-scale triaxial tests. These tests involved graded cyclic loading with different layers of geogrids and were conducted using three representative rubber contents of gravel mixtures. The study focused on analyzing the development and evolution laws of cumulative plastic strain and hysteresis curves. Key parameters of dynamic characteristics, such as dynamic elastic modulus and damping ratio were compared. The influence mechanism of the coupling effect between geogrid reinforcement and rubber gravel mixtures was also discussed. The results showed that geogrid reinforcement could slow down the increase of cumulative plastic strain under the same dynamic stress. This effect became more pronounced with an increasing number of geogrid layers. Additionally, increasing the rubber content in the mixture improved the ductility of the specimen, but it greatly reduced the bearing energy of the reinforced composite. The shape of the hysteresis curve was primarily influenced by the rubber content, becoming more full, inclined, and its arrangement becoming sparser as the rubber content increased. Geogrids improved the dynamic elastic modulus of the specimens, showing a significant growth stage with an increasing number of geogrid layers. The rubber content had a major impact on the initial value and change trend of the damping ratio. These findings provide valuable insights into the behavior and performance of geogrid-reinforced rubber gravel composites under dynamic loading conditions. They contribute to the understanding of how geogrids can enhance the bearing capacity and improve the overall stability of engineering structures constructed with rubber gravel mixtures.

Key words: geogrid, rubber gravel mixture, number of reinforcement layer, dynamic characteristic, large-scale triaxial tests