高速铁路飞砟问题影响因素与研究进展

Influence factors and research progress of ballast flight in high-speed railways

高速铁路有砟轨道飞砟问题严重限制列车运行安全和速度,然而迄今为止,飞砟现象的发生机制、演化过程与评估方法仍缺乏系统研究。针对高速铁路飞砟问题,首先对关键影响因素的作用机理与失效阈值等进行定量和定性分析;然后,梳理主要国家在科研项目、研究内容和创新技术等方面的研究历程,归纳欧盟标准和铁路互联互通技术规范等对飞砟问题的评估程序和技术指南,与我国现有技术规范进行对比分析。研究发现:1)飞砟问题研究兴起于21世纪初,随着高速铁路的发展,多个国家发现不同程度的道砟飞溅现象;2)列车运行速度、运营条件、轨道结构和道砟粒径形状等是飞砟问题的主要影响因素,其中时速300 km/h以上线路在高速风载和轨道振动作用下易发生飞砟现象。3)我国并没有专门针对飞砟问题的技术标准,但从列车和轨道结构优化等方面,出台了相应的技术要求,率先在时速250 km/h的高速铁路暂行规则中明确采用降低砟肩堆高和道床顶部位置的方法,对缓解飞砟问题起到了重要的作用。我国正处于“一带一路”发展的关键阶段,通过对飞砟机理和风险评估的研究,推动有砟轨道在不同速度等级、复杂工程环境的技术发展,对我国高速铁路“走出去”战略具有重要意义。

The ballast flight phenomenon on ballasted tracks of high-speed railways severely limits the safety and speed of train operation. However, so far, the occurrence mechanism, evolution process and evaluation method of the ballast flight phenomenon still lack systematic research. This paper conducted quantitative and qualitative analysis on the action mechanism and failure threshold of key influencing factors, then systematically combed the research history in scientific research projects, research content, and innovative technologies in the major ballast track construction countries. The EU standards and Technical Specification for Interoperability(TSI) certification about prevention and evaluation methods of ballast problems were summarized and compared with China existing technical specifications. The results are drawn as follows.(1) Since the beginning of the 2 000 s and up until very recently, the ballast flight phenomena are found because of the development of high-speed trains, then some researches have started investigations into some of the ballast flight mechanisms and optimization based on the rolling stock and infrastructure structure.(2) The train running speed, operating conditions, track structure and ballast particle size and shape are the main influencing factors of the ballast flight problem. The line above 300 km/h is prone to ballast moving and projection under the action of high-speed wind load and track vibration.(3) There are no national notified technical rules for ballast projection in China, but several optimization rules for train and track are formulated, for example, lowing the ballast profile and ballast shoulder in the line over 250 km/h,which can play an important role in alleviating the problem of ballast flight. China is at a critical stage of the development of the “Belt and Road”. Through research on ballast flight mechanisms and risk assessment, the development of ballasted track at different speeds and environments is promoted, which are of great significance to my country’s high-speed railway “going out” strategy.