细颗粒截断粒径对堆石体力学特性影响的数值模拟

发布时间：2018-08-23 21:18

【摘要】：建立考虑颗粒破碎的随机散粒体的SGDD数值模型,进行堆石体细颗粒截断粒径的敏感性分析,对三组不同截断粒径的数值试样进行不同围压的常规三轴试验,分析截断粒径对堆石体力学特性的影响并研究其细观机理.研究结果表明,在保持相对密度一致的条件下,数值试样的强度参数和变形参数随截断粒径的变化而单调变化;在细观层面上,颗粒体的各向异性演化规律与截断粒径密切相关.颗粒的配位数、接触失效率随截断粒径的减小而减小.截断粒径越小的试样含有的无效颗粒数越多,从数值试样的宏观强度、变形结果来考察数值剪切试验的精度,在本文数值试样的加载条件下,截断粒径取15mm时,其对宏观强度和变形的影响是可接受的.
[Abstract]:The SGDD numerical model of random granular particles considering particle breakage was established to analyze the sensitivity of the truncated particle size of the rockfill and the conventional triaxial tests with different confining pressures were carried out on three groups of numerical samples with different truncated particle sizes. The effect of truncated particle size on the mechanical properties of rockfill is analyzed and its meso-mechanism is studied. The results show that the strength parameters and deformation parameters of numerical specimens change monotonously with the change of truncated particle size under the condition of keeping the same relative density. The anisotropic evolution of particles is closely related to the truncated particle size. The coordination number and contact failure rate of the particles decrease with the decrease of the truncated particle size. The smaller the truncated particle size is, the more invalid particles are contained. The precision of the numerical shear test is investigated from the macroscopic strength and deformation results of the numerical specimen. Under the loading condition of the numerical sample in this paper, when the truncated particle size is taken as 15mm, Its effect on macroscopic strength and deformation is acceptable.
【作者单位】：武汉大学水资源与水电工程科学国家重点实验室;武汉大学水工岩石力学教育部重点实验室;
【基金】：国家自然科学基金(编号:51379161);国家自然科学基金优秀青年科学基金(编号:51322905)
【分类号】：TV641.4

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