基于离散单元法的碎石集料动力变形特性研究  

Study on Deformation Characteristics of Crushed Aggregate Subjected to Cyclic Loading Based on Discrete Element Method

作　　者：王鹏程 刘建坤 叶阳升 张千里 WANG Pengcheng;LIU Jiankun;YE Yangsheng;ZHANG Qianli(Railway Engineering Research Institute,China Academy of Railway Sciences Corporation Limited,Beijing 100081,China;School of Civil Engineering,Sun Yat-sen University,Guangzhou 510275,China)

机构地区：[1]中国铁道科学研究院集团有限公司铁道建筑研究所,北京100081 [2]中山大学土木工程学院,广东广州510275

出　　处：《铁道学报》2020年第11期161-166,共6页Journal of the China Railway Society

基　　金：国家自然科学基金(41801055);中国铁道科学研究院科技开发基金(2016YJ025)。

摘　　要：基于室内大型三轴动力剪切试验及颗粒流计算方法,分析了动荷载作用下碎石集料的永久变形特性与回弹变形特性,进一步研究了动荷载幅值、频率及集料密实程度对动变形特性的影响,并提出骨架孔隙比的概念用以评价级配间断较大的碎石集料的孔隙状态,主要结论包括:动荷载作用下,碎石集料的永久变形与回弹变形均在荷载作用初期增加较快,并最终趋于相对平稳;集料的永久变形随荷载幅值与频率的增加而增加;碎石集料最终相对稳定的回弹模量只与集料所受到的应力水平有关;骨架孔隙比的概念可评价含细小颗粒的间断级配碎石集料的孔隙状态,随骨架孔隙比的增加,集料的塑性变形越大,回弹模量越小。Based on the large scale indoor dynamic triaxial shear experiments and Particle Flow Code calculation,the permanent and resilient deformation behaviors of crushed aggregate under dynamic loading were analyzed respectively.The effects of amplitude and frequency of dynamic loading as well as the porosity state of the aggregate on dynamic deformation characteristics were also investigated.The effective void ratio was proposed to evaluate the void state of gap-graded crushed aggregate.The results show that both the permanent deformation and resilient deformation increase rapidly in the initial stage of the dynamic loading and then gradually to a constant state;The permanent deformation of aggregate increases with the increase of both amplitude and frequency of the dynamic load.The final constant resilient modulus of crushed aggregate is only determined by the stress state and the effective void ratio can be utilized to evaluate the void state of gap-graded aggregate.With the increase of effective void ratio,the greater the plastic deformation and the smaller the resilient modulus.

关 键 词：碎石集料 永久变形 回弹变形 骨架孔隙比 离散单元法 

分 类 号：O319.56[理学—一般力学与力学基础]