颗粒圆度对路用碎石集料破碎特征及力学性能的影响  

Influence of particle roundness on crushing characteristics and mechanical properties of road crushed stone aggregates

作　　者：何国栋 陈琛[2] 方传峰 袁正学 郭一鹏 HE Guodong;CHEN Chen;FANG Chuanfeng;YUAN Zhengxue;GUO Yipeng(China Railway Guizhou Engineering Co.,Ltd.,Gui’an New Area,Guizhou 561116,China;College of Civil Engineering,Xiangtan University,Xiangtan,Hunan 411105,China;School of Resource&Environment and Safety Engineering,Hunan University of Science and Technology,Xiangtan,Hunan 411201,China;School of Civil Engineering,Changsha University of Science and Technology,Changsha,Hunan 410114,China)

机构地区：[1]中铁贵州工程有限公司,贵州贵安新区561116 [2]湘潭大学土木工程学院,湖南湘潭411105 [3]湖南科技大学资源环境与安全工程学院,湖南湘潭411201 [4]长沙理工大学土木工程学院,湖南长沙410114

出　　处：《公路交通科技》2025年第3期95-103,共9页Journal of Highway and Transportation Research and Development

基　　金：国家自然科学基金项目(52008038);湖南省自然科学基金项目(2024JJ6429);湖南省教育厅科学研究项目(23C0061);中铁贵州工程有限公司科技研发项目(YF2313QL01D)。

摘　　要：【目标】隧道开挖产生的岩石弃渣常被用作路用碎石。研究颗粒圆度对弃渣路用碎石力学特征的影响,有助于优化道路结构的力学性能,减小因集料破碎和力学性能衰减而产生的道路破坏。【方法】基于3D扫描获取隧道弃渣处置后的碎石轮廓;通过三维缩放排除其他形状指标影响,筛选并构建了不同圆度指标的不规则颗粒模型;利用Voronoi多面体组成的集合体构建可破碎的路用颗粒;采用离散元软件PFC3D对路用碎石颗粒进行了三轴压缩试验模拟,以探究颗粒圆度对碎石集料的破碎特征和宏观力学特性的影响。【结果】路用颗粒集料的颗粒圆度越小,颗粒破碎程度越严重。相对破碎率随轴向应变增加而呈线性增长。颗粒集料的峰值剪切强度随颗粒圆度增加先达到峰值,后迅速降低。临界剪切强度随颗粒圆度增加而线性降低,颗粒破碎将导致更低的峰值剪切强度。碎石集料的体应变均表现为先剪缩,后剪胀,最后稳定的趋势。存在临界圆度为0.7,使得集料体应变的最大剪缩量和临界状态体应变均随颗粒圆度先增大而后减小。【结论】高圆度颗粒具有更好的力学性能,低圆度颗粒则更易破碎,可能导致道路结构力学性能下降。合理控制颗粒圆度对提高路用碎石的质量和道路耐久性具有重要意义。[Objective]The rock waste generated by tunnel excavation is often used as road aggregates.Studying the influence of particle roundness on mechanical characteristics of abandoned slag road aggregates can help optimize the mechanical properties of road structure,and reduce the road damage caused by aggregate crushing and mechanical performance degradation.[Method]The contour of crushed stones was obtained with 3D scanning.The influence of other shape indicators was excluded through 3D scaling.The irregular particle models with different roundness indicators were screened and constructed.The crushable road particles were constructed by using the aggregates composed with Voronoi polyhedron.The triaxial compression test simulation was conducted on road crushed stone particles by using PFC 3D.The influence of particle roundness on crushing characteristics and macroscopic mechanical properties of crushed stone aggregates was explored.[Result]The smaller the particle roundness of road particle aggregates,the more severe the degree of particle breakage.The relative crushing rate increases linearly with the increase of axial strain.The peak shear strength of particle aggregate first reaches the peak with the particle roundness increasing,and then rapidly decreases.The critical shear strength decreases linearly with the increase of particle roundness.The particle breakage will lead to lower peak shear strength.The volumetric strain of crushed stone aggregate shows a trend of first shear shrinkage,then shear expansion,and finally stability.The existence of critical roundness is 0.7.It results in both the maximum shear shrinkage of aggregate volume strain and the critical state volume strain increasing first and then decreasing with the particle roundness.[Conclusion]High roundness particles have better mechanical properties,while low roundness particles are more prone to breakage,which may lead to a decrease in the mechanical properties of road structures.Therefore,the reasonable control on particle roundness is of great sig

关 键 词：道路工程 碎石集料 离散元法 颗粒破碎 力学特性 

分 类 号：U414[交通运输工程—道路与铁道工程]