冲击碾压法加固堰塞坝料的室内模型试验研究

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

  • 摘要: 为丰富堰塞坝开发利用理论,探究适宜堰塞坝料的密实方法和设计参数,研究了冲击碾压方法对堰塞坝料的密实效果和密实机理。基于相似定律设计了不同冲击轮质量及牵引速度的天然堰塞坝料室内冲击碾压模型试验,综合采用宏-细观方法测试了冲击碾压后的动应力发展传播规律、变形特性、颗粒运动和加固效果等。试验结果表明:(1)冲击轮引起的冲击荷载为三角形脉冲荷载,产生的接触应力随着牵引速度和冲击轮质量的增大而增大,引起的地基动土应力随着碾压遍数的增加而增加;(2)冲击碾压对堰塞坝料地基表层的加固效果良好,地基内部动土应力和位移皆随深度迅速减小,深度3.6 m范围内的堰塞坝料强度提升明显;(3)提高冲击轮的速度对加固效果的影响更大,可以有效提高冲击动应力,进而使得冲碾加固效果向深层传递;(4)满足易贡堰塞坝料的冲击碾压参数为:冲击轮质量13.5 t,牵引速度3.46 m/s,碾压遍数12。

     

    Abstract: 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.

     

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