基于扣件阻力试验的高速铁路桥上无缝线路纵向力研究

Longitudinal force of CWR on high speed railway bridge based on fastener resistance test

通过试验得到随竖向荷载变化的小阻力扣件纵向阻力模型,基于有限元法和梁-轨相互作用理论建立CRTSⅠ型双块式无砟轨道-桥梁相互作用分析模型,采用考虑竖向荷载对扣件影响的点荷载模式模拟列车竖向荷载和制动荷载,得到列车竖向荷载、制动荷载作用下的无缝线路纵向力;并分析荷载布置方式、扣件纵向阻力模型和荷载模式等设计参数对钢轨纵向力的影响。研究结果表明:扣件在竖向有载情况下,随着竖向荷载增加,纵向阻力基本呈线性增长;扣件纵向阻力可取扣件竖向力与摩阻系数乘积,小阻力扣件摩阻系数偏安全取0.19;列车荷载作用下,同一转向架下2轮对影响范围可按8个扣件考虑,扣件分担荷载可取竖向荷载与扣件荷载分担比乘积;荷载布置方式对钢轨纵向力有一定影响,2种不同扣件纵向阻力模型计算的钢轨纵向力差别不大,ZK活载作用下的钢轨纵向力将轴重作用下的钢轨纵向力完全包络,对于高速铁路客运专线简支梁桥,列车荷载发展系数范围为2.36~3.33。

The longitudinal resistance model of small resistance fastener with vertical load change was obtained through experiments. Based on the finite element method and beam-rail interaction theory, the interaction analysis model of CRTS-I double-block ballastless track-bridge was established. The point load model considering the influence of vertical load on the fasteners was used to simulate the vertical and braking loads of trains, and the train vertical loads and braking loads were obtained. The influence of design parameters such as load arrangement,fastener longitudinal resistance model and load mode on rail longitudinal force was analyzed. The results show that the vertical resistance of fastener increases linearly with the increase of vertical load, and the vertical resistance of fastener can be taken as the product of vertical force and friction coefficient, and the friction coefficient of fastener with small resistance can be taken as 0.19. Under the action of train load, the influence range of two wheels under the same bogie can be considered as eight fasteners, and the load sharing ratio of fasteners can be the product of vertical load and fastener load sharing ratio. The load arrangement mode has certain influence on the longitudinal force of the rail. The difference of longitudinal forces calculated by two different fastener longitudinal resistance models is small. The longitudinal force of the rail under the live load of ZK completely envelops the longitudinal force of the rail under the axle load. For the simply supported beam bridge of the high-speed railway passenger dedicated line, the development coefficient range of the train load is 2.36-3.33.