制动条件下高速列车及桥上无砟轨道动力特性研究

With the increasing constructive application of the ballastless track CWR on bridge in the rapidly developing field of high-speed railway, the safety of the high-speed train on the bridge and the stability of the track and bridge structure are gradually becoming concerns of the railway departments and the passengers, for which, the issue of serious impacts of instantaneous braking shock of the high-speed train on the safety of train and the stability of track, roadbed and bridge has especially attracted much researching attention among scholars. In this project, considering the vertical interactions between vehicles, rails, ballastless track and bridge, based on the proposition of both the vehicle unit and ballastless track-bridge unit, the dynamic analysis model of the longitudinal and vertical coupling system of train-ballastless track-bridge is established for research into the dynamic characteristics of the high-speed train and ballastless track on bridge under braking condition. Meanwhile, the dynamic responses of the train, track and bridge to the braking of the ballastless track on the bridge are measured for the comparison of the theoretical calculation results and verification of the correctness and reliability of the calculation model and numerical calculation. It is wishfully predicted that the researching results of this project will be of great significance not only for guiding the design and operation maintenance of the ballastless track on the bridge, but also for offering support theoretically and technically for the safety of high-speed train running on the bridge and the stability of track and bridge structure.

随着高速铁路的快速发展，桥上无砟轨道无缝线路得到越来越多的应用，列车行车安全性以及轨道、桥梁结构的稳定性受到铁路部门和普通民众的广泛关注。特别是高速列车在制动过程中所产生的瞬时冲击作用，严重影响行车安全和轨道、桥梁结构的稳定，已经成为国内外学者研究的热点问题。本项目考虑车辆、钢轨、无砟轨道、桥梁的纵竖向作用关系，提出车辆单元和无砟轨道-桥梁单元，建立列车-无砟轨道-桥梁纵竖向耦合系统动力分析模型，研究制动条件下高速列车及桥上无砟轨道的动力特性；现场实测列车在桥上无砟轨道制动时列车、轨道、桥梁的动力响应，并与理论计算结果进行对比，验证理论计算的正确性和可靠性。预计本项目的研究成果对桥上无砟轨道设计、运营养护具有重要的指导意义，可为高速列车在桥上运行的安全性和轨道、桥梁结构的稳定性提供理论依据和技术支持。

高速列车在制动过程中所产生的瞬时冲击作用，严重影响行车安全和轨道、桥梁结构的稳定。针对这一热点问题，本项目考虑车辆、钢轨、无砟轨道、桥梁的纵竖向作用关系，提出了车辆单元和无砟轨道-桥梁单元，建立了列车-无砟轨道-桥梁纵竖向耦合系统动力分析模型，研究了制动条件下高速列车及桥上无砟轨道的动力特性；基于钢轨-轨道板-桥梁相互作用原理和有限元法，建立了多跨简支梁和大跨度连续梁桥上CRTSⅡ型板式无砟轨道无缝线路精细化空间耦合有限元模型，研究了列车制动条件下桥上无砟轨道无缝线路的纵向受力与变形特性，并对相关影响参数进行了分析。研究表明：列车制动过程中，轨道、桥梁结构的纵竖向位移和加速度均逐层递减，梁端处轨道结构的竖向振动比跨中处大；车体纵向加速度在整个制动过程中的峰值普遍较小，反映出高速动车组在桥上制动时具有良好的平稳性，但在停车瞬间，由于纵向加速度的反向突变，会使车内旅客感觉不适；在停车瞬间，轨道和桥梁结构的纵向位移和纵向加速度也会出现突变现象；为减少列车制动条件下桥梁及轨道结构纵向受力与变形，建议采用常阻力扣件、较大刚度的墩台支座，在设计桥上无砟轨道无缝线路时，轨道板/底座板应考虑其刚度折减问题，在施工过程中，必须保证轨道板/底座板的施工质量。本项目的研究成果对桥上无砟轨道设计、运营养护具有重要的指导意义，可为高速列车在桥上运行的安全性和轨道、桥梁结构的稳定性提供理论依据和技术支持。