PDF(Pubmed)
Abstract：
Particle geometric is a key parameter that defines the eometric attributes of calcareous sand particles and is intricately related to their mechanical traits, such as compression and shear. The scanning electron microscopy and digital imaging were applied to capture the microscopic properties and geometric projections of calcareous sand. The qualitative analysis, conventional statistical methods and fractal theory were employed to describe the geometric morphology of sand particles. Additionally, we analyzed the structural and physical traits of calcareous sand based on its unique biological genesis. We developed a hypothetical structural-physical model for calcareous sand. Our findings revealed the interwoven reticulation on the surface of calcareous gravel particles, along with an uneven distribution of pores on the external surface. As the particle size increased, the global profile factor decreased and the angularity increased. The critical threshold for the variations in flatness, surface roughness, and circularity was observed at a particle size of 5 mm, with the particle size having a relatively minor effect on these characteristics for particles smaller than 5 mm. The shape of the calcareous sand particles exhibited fractal characteristics, with fractal dimension serving as a measure of surface smoothness, particle breakage, and strength. These experimental results could significantly enhance our understanding of the mechanical behavior of calcareous sand.
摘要：
颗粒几何是定义钙质砂粒的几何属性的关键参数，并且与它们的机械特性密切相关，如压缩和剪切。应用扫描电子显微镜和数字成像技术捕获了钙质砂的微观特性和几何投影。定性分析,采用常规的统计方法和分形理论来描述砂粒的几何形态。此外,根据钙质砂独特的生物成因，分析了钙质砂的结构和物理特性。我们为钙质砂建立了一个假设的结构物理模型。我们的发现揭示了钙质砾石颗粒表面的交织网状，以及外表面孔隙的不均匀分布。随着颗粒尺寸的增加，全球剖面因子下降，角度增加。平坦度变化的临界阈值，表面粗糙度,并且在5毫米的颗粒尺寸下观察到圆形，对于小于5mm的颗粒,颗粒尺寸对这些特性具有相对较小的影响。石灰质砂粒的形态表现出分形特征,用分形维数作为表面光滑度的量度，颗粒破碎,和力量。这些实验结果可以显着增强我们对钙质砂的力学行为的理解。
