高速列车荷载与降雨入渗耦合作用下散体道床的力学行为及微观力学模型研究

The correct understanding and evaluation of the working process of ballast bed is a key scientific problem which must be solved in the application and promotion of ballast track in high-speed railway. However the current study lacks deep understanding of mechanics mechanism in high-speed railway ballast bed and lacks effective theoretical analysis model and evaluation method of behavior of ballast bed in working process and its influence on high-speed railway safety. From the macroscopic and microscopic perspective, taking the ballast track bed of high-speed railway as a research object, this project intends to adopt experimental study and theoretical analysis to analyze mechanical behavior and influence factors of ballast bed under the condition of combined action of train load and seepage effect. The project also intends to establish theory prediction model which could consider micro structure of ballast bed and its change of efficient medium mechanics behavior. And then the project conducts comprehensive research between track performance, offline basic conditions and the train running safety and quality which could draw a ballast bed evolution regularity of mechanical properties and the quantitative relationship between train running safety and quality to put forward maintenance standards of high-speed ballast track bed. The research conclusions will directly provide theoretical basis and technical guidance for design, operation and maintenance service of high-speed railway ballast track.

散体道床服役性能的正确认识及评估是高速铁路有砟轨道应用和推广必须解决的关键科学问题。然而当前研究对高速铁路散体道床的力学机理缺乏深入理解，对服役过程中散体道床的性能演变规律及其对高速铁路运营安全的影响还缺乏有效的理论分析模型和评价方法。本项目拟采用试验研究和理论分析相结合的手段，以高速铁路有砟轨道道床为研究对象，从宏观、微观两个方面，对列车荷载与降雨入渗耦合作用下的散体道床力学行为和影响因素进行分析，建立能考虑散体道床微观结构及其变化的高效率散体道床力学行为的理论预测模型，然后在此基础上开展道床性能、线下基础条件与列车行车安全和品质间三位一体综合研究，得出有砟道床力学特性的演化规律与列车行车安全和品质间的量化关系，进而提出高速有砟铁路道床养护维修分级控制标准。研究成果可直接为高速铁路有砟轨道的设计、运营和维修提供理论基础和技术指导。

散体道床服役性能的正确认识及评估是高速铁路有砟轨道应用和推广必须解决的关键科学问题。针对高速有砟铁路发展对散体道床提出的更稳、更强的要求，本项目以高速铁路有砟道床为研究对象，从宏观、微观两个方面，对列车动荷载、降雨入渗等多场效应影响下的散体道床力学行为和影响因素进行了试验研究和理论分析。通过开展铁路有砟道床相关力学特性的试验研究，获取了道砟劣化和脏污发展的演变规律，得到了道砟粒度分布、脏污程度、脏污材料类型以及脏污分布形式等影响下道砟集料排水性能的演化规律，探明了道床的含水量及脏污程度变化对散体道床力学性能的影响规律；提出基于真实几何特征的碎石道砟颗粒形态重构方法，建立能考虑散体道床微观结构及其变化的高效率散体道床力学行为的理论模型、降雨-列车荷载耦合的动力计算模型，开展了散体道床宏细观力学特性及动力响应的相关研究；构建了铁路翻浆冒泥计算模型以及翻浆冒泥病害发生的极限状态方程，探明了不同运营条件、不同下部基础条件下线路发生翻浆冒泥的风险，提出有利于防范翻浆冒泥病害的相关建议。研究成果可为有砟轨道设计及养护维修提供科学指导和理论依据，有利于高速铁路有砟轨道在国内外的推广和应用。