Model test study on landslide dam material improvement by rolling dynamic compaction

In order to enrich the development and utilization theory of landslide dam, explore the densification method and design parameters suitable for landslide material, and study the densification effect and mechanism of rolling dynamic compaction on landslide material, and based on the similarity law, the laboratory model test of rolling dynamic compaction on natural landslide material with different impact roller weights and traction speeds was designed. The macroscopic and meso-method was comprehensively used to test the development and propagation law of dynamic stress, deformation characteristics, particle movement and reinforcement effect after rolling dynamic compaction. The test results showed that the impact load caused by the roller was a triangular pulse load, the contact stress increased with the increasing traction speed and impact roller weight, and the dynamic soil stress of foundation increased with the increasing roller passes. Rolling dynamic compaction had a good reinforcement effect on the surface layer of landslide dam material foundation. The dynamic soil stress and displacement inside the foundation decreased rapidly with the depth, and the strength within the depth of 3.6 m increased significantly. The increasing speed of the impact roller had a greater improvement on the reinforcement effect, which can effectively improve the impact dynamic stress, and then transfer the reinforcement effect of roller to the deep layer. The rolling dynamic compaction parameters suitable for the Yigong landslide dam material are: the impact roller weight is 13.5 t, the traction speed is 3.46 m/s, and the number of passes is 12.