桥上无缝线路扣件纵向阻力试验研究

Experimental Study on Longitudinal Resistance of CWR Fasteners on Bridge

以高速铁路桥梁无砟轨道WJ‐7型和WJ‐8型小阻力扣件为研究对象,开展不同纵向加载速率以及竖向荷载条件下的纵向阻力试验,研究了纵向加载速率和竖向荷载对无缝线路扣件纵向阻力特性的影响,并给出了不同竖向加载条件下WJ‐7型和WJ‐8型小阻力扣件的纵向阻力-位移曲线,以用于梁轨相互作用精细化分析。结果表明:当竖向荷载不变时,纵向加载速率对两种小阻力扣件的动刚度和纵向阻力最大值影响较小;随着竖向荷载的增大,两种小阻力扣件的动刚度及纵向阻力均明显增大,其弹塑性临界点也逐渐增大;与竖向无载工况相比,竖向荷载为50 kN时,WJ‐7型小阻力扣件最大纵向阻力、弹塑性临界点增幅分别为177.74%和87.71%,WJ‐8型小阻力扣件增幅分别为320.44%和118.88%。

Taking WJ-7 and WJ-8 low resistance fasteners for ballastless track of high speed railway bridges as the research objects,the longitudinal resistance tests of fasteners under different longitudinal loading rates and vertical loads were carried out.The influence of longitudinal loading rate and vertical load on the longitudinal resistance characteristics of continuous welded rail(CWR)fasteners was researched.And the longitudinal resistance-displacement curves of WJ-7 and WJ-8 low resistance fasteners under different vertical loads were given,which can be used for refined analysis of beam-rail interaction.The results show that when the vertical load is constant,the longitudinal loading rate has little effect on the dynamic stiffness and the maximum longitudinal resistance of the two types of low resistance fasteners.With the increase of vertical load,the dynamic stiffness and longitudinal resistance of the two types of fasteners increase obviously and the elastic-plastic critical points of the two types of fasteners also increase.Compared with the vertical no-load condition,when the vertical load is 50 kN,the maximum longitudinal resistance and elasticplastic critical point of WJ-7 low resistance fastener increases by 177.74%and 87.71%respectively,and those of WJ-8 low resistance fastener increases by 320.44%and 118.88%respectively.