高速铁路飞砟机理及有砟道床断面结构优化研究

Ballast flight is induced from aerodynamic wind and dynamic force under high speed train, setting obstacles for ballast bed application and development in high speed railway (HSR). Depending on railway engineering, the ballast bed macro-micro characteristics under dynamic and aerodynamic effects is investigated in the project, aiming to illustrate the mechanism of ballast flight, and optimize the structure of ballast bed. The ballast flight risk is assessed by reliability method of stochastic process. To be specific, the collaborative research of ballast bed mechanics and wind engineering is carried out: .(1) Collaborative research of granular dynamic and aerodynamic on ballast flight, conducting ballast bed dynamic and aerodynamic experiments, both wind tunnel tests and site tests;.(2) Clarification of ballast flight mechanism and influence factors, applying stochastic process and reliability analysis method for risk assessment, setting foundation for HSR ballast flight risk evaluation and control;.(3) Comprehensive development of ballast flight counteraction method and measures, optimizing HSR ballast bed cross section structure(shoulder ballast height, shape, width and crib ballast), sleeper shape(areosleeper), ballast PSD and compaction etc., which directs HSR ballast bed design, operation and maintenance.

飞砟是高速铁路列车动力和列车风空气动力共同作用下产生的破坏性现象，严重制约高速有砟道床应用与发展。本项目拟基于铁道工程学科，研究列车动力、空气动力多场共同作用下有砟道床力学宏细观特性，阐明飞砟机理，优化高速铁路有砟道床断面结构，量化飞砟随机过程可靠度进行风险评估。具体地，拟开展有砟道床动力特性和风工程研究，包括：（1）协同研究散体动力、空气动力作用下飞砟机理，开展有砟道床空气动力学和动力特性测试，包括风洞试验与现场试验；（2）阐明飞砟机理及影响因素，应用随机过程理论及可靠度分析方法，为高速铁路飞砟风险评估奠定基础；（3）综合拓展飞砟防治方法与措施，优化高速铁路有砟道床断面结构（砟肩堆高、形状、宽度、枕心道砟），轨枕形状(空气动力学优化轨枕)，道砟级配与密实度等，指导高速铁路有砟道床设计、运营与维修。

高速铁路有砟道床，存在主要两个方面的问题。（1）道床劣化（2）飞砟问题。有砟道床由碎石道砟所构成，力学特性存在明显的离散性，有砟道床问题的根本来源可归纳为由列车振动荷载引起的道床振动，导致道砟劣化、破碎产生累积变形、不满足列车高速行驶的平顺性要求，以及近年来，列车风荷载与振动的协同作用下可能发生道砟飞溅问题。采用空气动力学,风洞试验,离散单元法,轨道力学试验,随机过程可靠度方法等进行了多角度协同研究，共计产生标注SCI和期刊论文20篇以上，发明专利2项，培养研究生5名，较好的完成了研究项目，研究成果在伊朗德伊高铁/俄罗斯莫喀高铁得到了应用和体现，能满足速度350km/h及以上的运营要求。