循环荷载下道砟破碎老化离散单元法仿真分析
doi: 10.3969/j.issn.0258-2724.2012.02.003
DEM Simulation of Ballast Degradation and Breakage under Cyclic Loading
-
摘要: 为从细观力学上反映道砟与轨枕的相互作用机理以及道砟颗粒的破裂过程,建立了道砟-轨枕离散单元模型,对循环荷载作用下道砟破碎老化进行了仿真.道砟由不规则圆盘簇组成,分为不可破裂与可破裂颗粒,并施加单调荷载和循环荷载.结果表明:相同荷载下,加载时轨枕与道砟的接触力大于卸载时;破碎道砟颗粒集中在轨枕下方,道砟颗粒破裂产生的沉降是造成轨枕沉降的主要原因,沉降量随道砟颗粒强度的降低而增大.Abstract: In order to reflect the micro-mechanism of ballast-sleeper interaction and the process of ballast breakage, a 3-D ballast-sleeper model based on the discrete element method (DEM) was established, and ballast degradation and breakage under cyclic loading were simulated. In this model, irregular ballast particles are modeled by clusters, they are divided into two kinds, i.e., unbreakable and breakable, and ballast is respectively subjected to monotonic and cyclic loads. The research results show that under the same load, contact force between ballast and sleeper is larger when the ballast is loaded than that when it is unloaded. The crushed clusters mainly appear underneath the sleeper, particle crushing is a major factor for sleeper settlement, and the sleeper settlement increases when ballast strength reduces.
-
[1 INDRARATNA B, SALIM W. Mechanics of ballasted rail tracks: a geotechnical perspective[M. London: Taylor Francis/Balkema, 2005: 3-4. [2 雷晓燕. 道床极限承载力的有限元分析[J. 铁道学报,1992,14(1): 56-61. LEI Xiaoyan. A finite element analysis on the ultimate load of ballast[J. Journal of the China Railway Society, 1992, 14(1): 56-61. [3 SHAER A. Permanent settlement analysis of ballasted railway tracks: dynamical approach[D. Paris: National School of Bridges and Roads, 2002. [4 ANDERSON W F, KEY A J. Model testing of two-layer railway track ballast[J. Journal of Geotechnical and Geo-environmental Engineering, 2000, 126(4): 317-323. [5 AZMA . Numerical study of polyhedron granular material: quasi-static rheology, tamping applica-tion[D. Montpellier: Universit Montpellier, 2007. [6 TUTUMLUER E. Aggregate shape effects on ballast tamping and railroad track lateral stability[C∥Proceedings of AREMA. Louisville, KY: American Railway Engineering and Maintenance of Way Associa-tion, 2006: 17-20. [7 LOBO-GUERRERO S, VALLEJO L E. Discrete element method analysis of rail track ballast degradation during cyclic loading[J. Granular Matter, 2006, 8(3/4): 195-204. [8 LU M, McDOWELL G R. The importance of modelling ballast particle shape in the discrete element method[J. Granular Matter, 2007, 9(1/2): 69-80. [9 中华人民共和国铁道部. TB/T21402008 铁路碎石道砟[S. 北京:中国铁道出版社,2008. [10 LIM W L. Mechanics of railway ballast behaviour[D. Nottingham: Nottingham University, 2004. [11 Itasca Consulting Group Inc. PFC2D user's manual: version 3.1[M. Minneapolis, MN: Itasca Consulting Group Inc., 2006: 49-57. [12 CUNDALL P A, STRACK O D L. A discrete numerical model for granular assemblies[J. Geotechnique, 1979, 29(1): 47-65. [13 JING G Q. DEM simulations of ballast under cyclic traffic loading[D. Rennes: Institute National des Sciences Appliques de Rennes, 2009. [14 ASPREY J D. Cost effective maintenance of track[C∥Automatic Track Top and Alignment. London: Railway Industries Association, Fourth Track Sector Course, 1992: 174-176. -
点击查看大图
计量
- 文章访问数: 1451
- HTML全文浏览量: 71
- PDF下载量: 531
- 被引次数: 0
下载: