胶结土石混合体力学特性的块石形状效应细观机理分析

发布时间：2018-01-03 16:02

本文关键词：胶结土石混合体力学特性的块石形状效应细观机理分析　出处：《固体力学学报》2015年06期 　论文类型：期刊论文

【摘要】：考虑块石形状为球体、正方体和长方体三种情况,通过正方体与球体相比较来探究块石不同棱角度对胶结土石混合体力学特性的影响,通过长方体与正方体相比较来探究块石不同球度对胶结土石混合体力学特性的影响.首先,基于不规则颗粒三维离散元精细模拟技术实现了正方体和长方体块石数值模型的建立;然后建立含石量为30%和80%的块石形状分别为球体、正方体和长方体的胶结土石混合体三维离散元随机结构模型;最后,对土石混合体大三轴试验进行颗粒流数值模拟,获得了不同含石量、不同块石形状下胶结土石混合体的强度特征和变形特征,并分别就低、高两种含石量下块石形状对土石混合体力学特性影响的细观机理进行了深入地分析.结果表明:块石含量和形状均会显著影响胶结土石混合体的力学特性,并且两者间具有复杂的交互作用;微裂纹、块石颗粒平均旋转量、应变能和摩擦功等的演化规律能够很好地从细观水平上反映块石形状影响的作用机理.
[Abstract]:Considering that the rock shape is spherical, cuboid and cuboid, the influence of different edge angles of block stone on the mechanical properties of cemented soil-rock mixture is explored through the comparison of cube and sphere. Through the comparison of cuboids and cuboids to explore the impact of different sphericity of block stone on the mechanical properties of cemented soil-rock mixture. First of all. The numerical model of cuboid and cuboid block is established based on 3D discrete element fine simulation technology of irregular particles. Then, the three dimensional discrete element stochastic structure model of cemented earth and rock mixture with 30% and 80% rock contents is established, which is spherical, cuboid and cubohedral, respectively. Finally, the particle flow numerical simulation is carried out on the large triaxial test of soil-rock mixture, and the strength and deformation characteristics of cemented soil-rock mixture with different rock content and different rock shape are obtained, respectively. The effect of rock shape on the mechanical properties of soil-rock mixture is analyzed in detail. The results show that the content and shape of block stone can significantly affect the mechanical properties of cemented soil-rock mixture. And there is a complex interaction between the two; The evolution laws of microcracks, mean rotation of rock particles, strain energy and friction work can well reflect the mechanism of the effect of rock shape on the meso level.
【作者单位】：武汉大学土木建筑工程学院;中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室;
【基金】：国家自然科学基金面上项目(41272342)资助
【分类号】：TU43
【正文快照】： 0引言土石混合体(Soil-rock mixture,简称SRM)是指第四纪以来形成的,由具有一定工程尺度、强度较高的块石、细粒土体及孔隙构成且具有一定含石量(Rock block proportion,简称RBP)的极端不均匀松散岩土介质系统[1].土石混合体在自然界中分布非常广泛,地球上绝大多数滑坡体都是

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