Li Huiqi, McDowell Glenn R
Nottingham Centre for Geomechanics, University of Nottingham, Nottingham, UK.
Granul Matter. 2018;20(2):26. doi: 10.1007/s10035-018-0795-0. Epub 2018 Mar 17.
It has recently been reported that under sleeper pads (USPs) could improve ballasted rail track by decreasing the sleeper settlement and reducing particle breakage. In order to find out what happens at the particle-pad interface, discrete element modelling (DEM) is used to provide micro mechanical insight. The same positive effects of USP are found in the DEM simulations. The evidence provided by DEM shows that application of a USP allows more particles to be in contact with the pad, and causes these particles to transfer a larger lateral load to the adjacent ballast but a smaller vertical load beneath the sleeper. This could be used to explain why the USP helps to reduce the track settlement. In terms of particle breakage, it is found that most breakage occurs at the particle-sleeper interface and along the main contact force chains between particles under the sleeper. The use of USPs could effectively reduce particle abrasion that occurs in both of these regions.
最近有报道称，轨枕垫板（USPs）可以通过减少轨枕沉降和降低颗粒破碎来改善有砟轨道。为了弄清楚颗粒与垫板界面处发生了什么，采用离散元建模（DEM）来提供微观力学见解。在DEM模拟中发现了轨枕垫板的相同积极效果。DEM提供的证据表明，使用轨枕垫板会使更多颗粒与垫板接触，并使这些颗粒将更大的横向荷载传递到相邻道砟，但在轨枕下方传递较小的垂直荷载。这可以用来解释为什么轨枕垫板有助于减少轨道沉降。就颗粒破碎而言，发现大多数破碎发生在轨枕与颗粒的界面处以及轨枕下方颗粒之间的主要接触力链沿线。使用轨枕垫板可以有效减少在这两个区域发生的颗粒磨损。
