吹砟车维修机理离散元仿真与应用

Simulation and Application of Maintenance Mechanism of Ballast Blowing Car with DEM

研究目的:吹砟车维修在轨枕下方补充硬质小道砟,避免捣固道砟和破损,工程实践上能消除道砟记忆效应。但在微观力学层面缺少对吹砟维修作业方式和效果应用研究,为微观力学层面研究吹砟车工作原理与养护效果,采用颗粒流离散元方法建立道砟-轨枕三维箱体模型,其中采用与道砟颗粒大小一致不规则球体组合代替道砟,借以更加真实模拟道砟颗粒之间咬合力,在轨枕单调加载下研究吹砟养护前后道床力学特性。研究结论:吹砟维修作业前后微观力学分析表明,吹砟车维修能降低轨枕-道砟接触层作用力,对轨枕-道砟沉降影响不大,从数值原理上定量揭示吹砟车维修作业力学原理;与捣固维修作业相比,吹砟维修是一种效率高、成本低、开通速度快、环保维修方法。

Research purposes： The maintenance by the ballast blowing ear needs to supply the small hard ballast under sleeper bottom to avoid tamping and breaking the ballast and eliminate the ballast memory effect. From the microscopic mechanics, there is a little research on the maintenance mode of blowing ballast and on its applicable effect. In order to research the working principle and the maintenance effect of ballast blowing car from the microscopic mechanics, the DEM was used to produce the ballast - sleeper 3 D box model to simulate the ballast blowing. Ballast particles were made of real size irregular clumps to simulate the ballast interactions more precisely, and the research was done on the mechanic effect of the roadbed under monotonic loading on the sleeper before and after the ballast blowing. Research conclusions： The micro -mechanics simulation results showed that the contact force between sleeper and ballast could be reduced by blowing ballast and the ballast blowing had a little influence on the sleeperballast deformation. So the mechanics principle of the ballast blowing car operation was revealed quantitatively from the numerical value principle. Compared with tamping ballast, the ballast blowing is high -efficient, rapid, low -cost and environment protected maintenance way.