To analyze more accurately the dynamic response of sleeper and ballast bed under heavy haul railway train load, this paper uses parallel bonded spherical elements to simulate concrete sleeper structure, which can realistically simulate the load transfer from sleeper to load, and rigid clusters with realistic shape to simulate ballast particles. The reliability of the model is tested by verifying the vertical stiffness and lateral resistance and comparing them with the experimental data. The train load is applied to the area on the sleeper in contact with the rail to study the settlement and vibration response of the sleeper and the ballast bed. The results show that the vertical displacement of the sleeper is different at each place under the train load, the displacement of the sleeper in the area under the rail is significantly larger than the shoulder and the center of the sleeper, and the bending deformation of the sleeper is W-shaped; the displacement and vibration amplitude of the sleeper will increase when the train speed increases; the internal stress of the sleeper under the rail is much larger than the center of the sleeper, the influence degree of sleeper center will increase with the increase in train speed. The ballast particle displacement and vibration will decrease with the increase in the ballast bed depth, and the ballast displacement and velocity in the area below the rail action is larger than that in the ballast shoulder and bed center area.

为了更准确地分析重载铁路列车荷载作用下轨枕和道碴床的动态响应，本文采用平行粘结球形单元模拟混凝土轨枕结构，可以真实地模拟从轨枕到荷载的荷载传递，并且刚性簇形状逼真。模拟道碴颗粒。通过验证竖向刚度和侧向阻力并与实验数据进行比较，检验了模型的可靠性。将列车载荷施加到枕木上与钢轨接触的区域，以研究枕木和道碴床的沉降和振动响应。结果表明:在列车荷载作用下,轨枕各处竖向位移不同,轨下区域轨枕位移明显大于轨肩和轨枕中心,轨枕弯曲变形较大。枕木为W形；当列车速度增加时，轨枕的位移和振动幅度会增大；轨下轨枕的内应力远大于轨枕中心的内应力，轨枕中心的影响程度随着列车速度的增加而增大。道碴颗粒的位移和振动会随着道床深度的增加而减小，且轨作用下方区域的道碴位移和速度大于道肩和道床中心区域的道床位移和速度。