Due to imperfect design norms and guidelines for China’s truck escape ramp, previous studies have not been able to reflect the effect of wheel subsidence process on the deceleration of runaway vehicles. A discrete element method was used to establish an aggregate discrete element and a wheel discrete element. The three-dimensional discrete element model for an aggregate-wheel combination was established based on a particle flow code in three dimensions on a software platform using the “FISH” language. The microscopic parameters of the aggregate discrete element particles and wheel discrete element particles were calibrated using a simulated static triaxial compression test and real vehicle test data, respectively. Four sets of numerical simulation tests were designed for analyzing the influence of the aggregate diameter, grade of the arrester bed, truckload, and entry speed on the wheel subsidence depth and stopping distance of runaway vehicles. The results indicate that the smaller the aggregate diameter and entry speed and the greater the truckload and grade of the arrester bed, the more easily the wheel falls into the gravel aggregate, the better the deceleration effect, and the smaller the stopping distance. As the wheel subsidence depth increases, the speed at the unit stopping distance decreases more quickly. The maximum subsidence depth mainly depends on the truckload. The research results can provide a theoretical basis for the design of the arrester bed length and the thickness of the aggregate pavement in a truck escape ramp.

由于我国卡车逃生坡道设计规范和指南不完善，以往的研究未能反映车轮下沉过程对失控车辆减速度的影响。采用离散元法建立了聚合离散元和车轮离散元。采用“FISH”语言在软件平台上基于三维颗粒流代码建立了骨料-轮组合的三维离散元模型。分别利用模拟静态三轴压缩试验和实车试验数据对骨料离散元颗粒和车轮离散元颗粒的微观参数进行了标定。设计了四组数值模拟试验，分析了避雷器骨料直径、避雷器床等级、车辆装载量、进入速度对车轮下沉深度和失控车辆制动距离的影响。研究结果表明:集料直径和进入速度越小,避雷器床的载重和坡度越大,车轮越容易陷入砾石中,减速效果越好,制动距离越小。随着车轮下沉深度的增加，单位停车距离处的速度下降得更快。最大沉降深度主要取决于卡车装载量。研究结果可为卡车逃生坡道避雷器床长和骨料路面厚度的设计提供理论依据。