温度荷载作用下桥上CRTS Ⅱ型板式轨道纵向力学特性研究

Study on longitudinal mechanical characteristics of CRTS Ⅱ slab track on bridge under the temperature load

利用有限元软件ANSYS建立温度荷载作用下桥上CRTS II型板式无砟轨道结构体系各部件纵向相互作用分析模型。模型中钢轨、轨道板、底座板、梁体、桥墩均采用梁单元模拟,各结构层之间的连接采用弹簧单元模拟。以一座高速铁路混凝土连续梁桥为例,分析桥梁温度荷载作用下,轨道及桥梁结构的力学特性,并针对相关因素对各结构层受力与变形的影响进行了研究。研究结果表明:当梁体温升幅度达到一定值以后,轨道结构纵向力不再明显增大;"分离板模型"能更好反映CA砂浆黏结状态对轨道和桥梁受力特性的影响;滑动层摩擦大数增大,将大幅度增加轨道与桥梁结构的受力;轨道板宽接缝开裂导致钢轨、底座板纵向受力以及轨道板位移的增大。

A model to study the longitudinal mechanical characteristics of CRTS II slab track on bridge under the temperature load was established by ANSYS in this paper.The rail,slab,foundation plate,box bridge and bridge pier were simulated by beam element,while the connection between layers were simulated by spring ele-ment in the model.Taking a continuous beam bridge on high speed railway as an example,the longitudinal me-chanical characteristics of track structure and bridge structure,as well as the influences of several factors on the force and displacement of each component were analyzed by virtue of the model.The results show that：（1）The longitudinal forces of track structure will no longer increase obviously when the temperature on bridge reaches a certain value.（2）“Separate Slab Model”can simulate the influence of longitudinal mechanical characteristics of track structure and bridge structure by cement emulsified asphalt mortar.（3）The force of track structure and bridge structure will increase greatly,as the friction coefficient of sliding layer increases.（4）The cracking at wide juncture will increase the force of rail and foundation plate and the displacement of slab.