温度梯度荷载对桥上无砟轨道几何形位的影响分析

我国在设计桥上无缝线路时,桥梁温度荷载按照相关规范规定采用均匀温度荷载,这与桥梁在自然环境中所受到的温度梯度荷载存在一定的差异。基于梁轨相互作用原理,利用有限元方法,建立桥上CRTSⅢ型板式无砟轨道有限元模型,分别计算分析在均匀温度和竖向温度梯度作用下桥梁变形对无砟轨道结构几何形位的影响,有益于进一步深入研究桥梁温度荷载的合理取值。结果表明:与均匀温度荷载相比,竖向温度梯度荷载对桥上无砟轨道几何形位影响很大,且主要影响桥上无砟轨道的高低几何形位,对无砟轨道的水平几何形位也有一定影响,因此建议在设计桥上无缝线路时,考虑桥梁温度梯度荷载,并对桥上无砟轨道结构的几何形位进行限制。

Study on the Influence of Temperature Gradient Load on the Geometry of Ballastless Track on Bridge

According to the relevant codes about CWR of China,the temperature load applied on bridge is uniform,which is somewhat different from the temperature gradient load in natural environment.Based on the principle of interaction between beam and rail and the use of the finite element method,the model of CRTSIII slab ballastless track on bridge is established and the influences of the deformation of the bridge generated by the uniform temperature and the vertical temperature gradient on the geometry of ballastless track on bridge are calculated respectively,which is beneficial to further study and rational selection of bridge temperature load.The results show that in comparison with the uniform temperature load,the vertical temperature gradient on bridge imposes greater influence on the ballastless track geometry,affects mainly the longitudinal level of ballastless track and also has some influence on level geometry.Thus,when designing the CWR on bridge,it is recommended to consider the temperature gradient load on bridge and confine the ballastless track geometry.