泥石流宽级配砾石土结构特征实验研究

泥石流堆积物是一种宽级配砾石土，深入研究其结构特征和渗透特性，具有重要的理论和实践意义。根据粗细颗粒的含量，提出了接触式堆积、紧密堆积和基底式堆积三种结构类型，并通过实验进行了验证和分析；分析表明，细粒含量是决定宽级配土结构的关键。击实实验显示土中细颗粒含量达到16.52%时，干密度最大；渗透实验也表明此时其渗透性接近细粒土的渗透性；数值模拟表明，细颗粒含量达到22.23%时，孔隙率最小。理论分析和实验研究认为，宽级配砾石土中紧密堆积结构的细颗粒含量上限应为20%，超过这个含量，粗颗粒的骨架作用会被减弱，强度降低。

Experimental study on packing structural characteristics of wide-graded gravel soil in debris flow

Debris flow deposits are wide-graded gravel soils, and studying their structural and permeability characteristics is of great theoretical and practical importance. Based on the content of coarse and fine grains, three structural types of contact packing structure, close packing structure, and matrix packing structure were proposed and verified through experiments. The analysis revealed that fine particle content is the key factor determining the structure of wide-graded soils. The compaction test indicated that on the condition that the content of fine particles in the soil reached 16.52%, the dry density was the largest; the infiltration test also illustrated that its permeability was close to that of fine-grained soil at this time; Numerical simulations indicated that the minimum porosity is reached when the fine particle content is 22.23%. Theoretical analysis and experimental research reveal that the upper limit for the fine particle content of the densely packed structure in wide-graded gravel soil should be 20%. If this limit is exceeded, the skeleton effect of coarse particles will be weakened, resulting in reduced strength.