考虑级配影响的粗粒料压缩破碎特性试验

采用分形维数和级配宽度作为级配的量化指标，通过粗粒料的侧限压缩试验，研究级配对密实粗粒料的堆积、变形以及破碎特性的影响规律。试验结果表明，粗粒料的最大干密度和低应力下的压缩模量均随着分形维数的增大先增大后减小，在分形维数为2.2附近存在极大值；同时，两者均随着级配宽度增大而增大。粗粒料的破碎强度可通过双对数坐标下的拐点表征，破碎强度随着分形维数与级配宽度的增大而增大；破碎强度越高，颗粒破碎率越小；不同级配的粗粒料充分破碎后的最终级配都收敛于唯一的分形分布。

Experimental study on compression and crushing characteristics of coarse granular materials considering influence of gradations

Using the fractal dimension and the gradation width to quantify the gradation, the influence of gradation on the maximum dry density, the oedometric modulus and the particle breakage is investigated through a series of oedometric compression tests. The test results show that the maximum dry density of coarse-grained material increases first and then decreases with the increase of fractal dimension and reaches a maximum value when the fractal dimension is near 2. 2. Meanwhile, the maximum dry density of coarse grain increases with the increase of gradation width. The oedometric modulus under a low-stress level is influenced similarly by the gradation. Denoting the transitional stress in double logarithmic coordinates as the crushing strength, the crushing strength of coarse-grained materials increases with the increase of fractal dimension and gradation width. The greater the crushing strength, the smaller the breaking rate of particle. The final gradation of coarse aggregate with different initial gradations converges towards a unique ultimate fractal distribution.