块石含量和空间分布对土石混合体抗剪强度影响的离散元分析

发布时间：2018-04-04 00:35

本文选题：土石混合体　切入点：直剪试验　出处：《工程力学》2017年06期

【摘要】：土石混合体的抗剪强度在很大程度上取决于其块石的含量、空间分布、形态等参数。该文采用球体单元模拟土颗粒,通过组合颗粒单元构造非规则形态的块石,对不同含石量和块石空间分布下土石混合体的直剪过程进行了离散元数值模拟。计算结果表明,在低含石量下,土石混合体的抗剪强度随含石量的增加而增加;在中含石量下,受块石空间分布的影响,其抗剪强度呈现很强的波动性;在高含石量下,其抗剪强度显著增强,波动性相对较小。抗剪强度在中高含石量下波动现象的细观机理是块石空间分布影响下的力链结构特性。当块石的空间分布使其形成较强力链结构时,抗剪强度较高;反之,块石间的力链结构不稳定,抗剪强度相对较低。以上研究有助于从细观尺度揭示土石混合体变形和剪切强度特性的内在机理。
[Abstract]:The shear strength of soil-rock mixture depends to a great extent on its mass content, spatial distribution, shape and other parameters.In this paper, the spherical element is used to simulate the soil particles. The discrete element numerical simulation is carried out for the direct shear process of the soil-rock mixture under different rock content and spatial distribution.The results show that the shear strength of soil-rock mixture increases with the increase of rock content under the condition of low rock content, the shear strength is highly fluctuated under the influence of the spatial distribution of massive stone under the medium rock content, and at high rock content, the shear strength of soil-rock mixture increases with the increase of rock content.The shear strength is significantly enhanced, and the volatility is relatively small.The meso-mechanism of shear strength fluctuation under the medium and high rock content is the structural characteristics of the force chain under the influence of the spatial distribution of the block stone.When the spatial distribution of the block makes it form a stronger chain structure, the shear strength is higher, whereas the force chain structure between the blocks is unstable and the shear strength is relatively low.The above studies are helpful to reveal the internal mechanism of deformation and shear strength characteristics of soil-rock mixture in meso scale.
【作者单位】：大连交通大学土木与安全工程学院;大连理工大学工业装备结构分析国家重点实验室;
【基金】：国家重点基础研究发展规划项目(2010CB731502) 国家自然科学基金项目(U1234209,11572067,11672072)
【分类号】：TU43

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