特殊桥梁结构无缝线路附加纵向力计算方法

Calculation Method of Additional Longitudinal Forces of CWR for Special Bridge Structure

在温度荷载和列车荷载作用下,桥梁和轨道设计应考虑梁体与无缝线路相互作用而产生的附加纵向力。可以采用大型有限元软件建立三维空间耦合的简易实体模型,但对U形梁、变截面梁、钢桁梁等特殊复杂桥梁结构,建模难度大,且模型通常与实际桥梁结构差异较大,影响计算准确性。本文通过理论分析,基于有限元刚度法(位移法),建立无缝线路附加纵向力简易模型,直接加载位移,并利用梁、轨位移与纵向阻力间关系,计算无缝线路各种附加纵向力。选取城市轨道交通、高速铁路2个具体实例,将位移数据通过程序加载至无缝线路模型,求解出附加纵向力。该方法同样适用于其他一些特殊复杂桥梁,弥补了原有模型的不足,计算也更精准简洁。

Under the action of temperature load and the train load,additional longitudinal forces caused by interaction of bridge and CWR should be taken into account during the design of bridge and track. Large finite element software can be used to establish a simple solid model of three-dimensional space coupling.However, it is difficult to model especial complex bridge structures such as U-shaped beam,variable cross-section beam and steel truss beam.Moreover,the model is usually significantly different from the actual bridge structure,which affects the calculation accuracy.By theoretical analysis,a simplified model for the calculation of the additional force of CWR was established based on the finite element stiffness method（ displacement method）.This model loads the displacement directly,the additional longitudinal force of CWR is calculated by analyzing the relationship between beam,rail displacement and longitudinal resistance. In this paper,through two examples of urban rail transit and high speed railway projects,the displacement data were loaded by the program to the CWR model and the additional longitudinal forces were calculated as the output.This method could also be applid to other special complex bridges,covering the shortage of conciseness of existing calculation models.