高速铁路飞砟风险等级模糊层次综合评判

Fuzzy AHP comprehensive evaluation of ballast flight on high-speed railway

高速铁路飞砟是制约有砟轨道发展的重要原因之一。飞砟发生过程和运动规律存在着不确定性,受到列车空气动力、轨道响应、地面和天气条件等多种因素的影响。针对既有飞砟风险评价指标单一的不足,通过系统梳理高速铁路飞砟风险影响因素,提出基于模糊层次综合评价的高速铁路飞砟风险评估方法。首先,梳理高速铁路有砟轨道道砟颗粒迁移-飞溅的影响因素,构建飞砟风险等级评价指标体系和递阶层次评价结构;然后,采用层次分析法计算风险评价指标体系中风险因素的权重;在此基础上,选取合适的隶属度函数计算隶属度向量并进行集化,得到最终综合评估值,以此确定飞砟风险级别。通过使用以上方法对欧盟发生飞砟的典型路段以及我国银西高铁有砟道床试验段进行风险评估,结果表明:欧盟2001—2010年发生飞砟的线路风险级别高,有7条线路处于Ⅳ级风险,1条线路处于V级风险;随着列车和轨道结构的不断优化,现在高铁飞砟风险逐渐降低,尤其是我国银西高铁建成的新型有砟轨道结构试验段,通过优化道砟粒径、取消砟肩堆高、降低道床顶面位置等措施大幅度降低飞砟风险。本方法可将边界不清的因素定量化,有效评判高速铁路飞砟风险级别,并可指导高速列车和有砟轨道结构优化,保障列车安全平稳运行。

Ballast flight is one of the important reasons restricting the development of ballasted track in highspeed railway.The occurrence and motion characteristics of ballast flight on high-speed railway are characterized by uncertainty,influenced by a range of factors including train aerodynamics,track response,ground effects,and weather conditions.Aiming at the shortcomings of single ballast risk evaluation index of the existing research,a fuzzy hierarchical comprehensive evaluation-based risk assessment method was proposed by systematically sorting out the influencing factors of ballast flight for high-speed railway.First,the influencing factors of ballast particle migration-flying on ballasted tracks of high-speed railways were examined,and a risk level assessment index system for ballast flight was constructed along with a hierarchical evaluation structure.Next,the Analytic Hierarchy Process(AHP)was applied to calculate the weights of risk factors within the risk assessment index system.Based on this,appropriate membership functions and expert evaluation were combined to obtain membership degree vectors.These fuzzy evaluation vectors were then aggregated to derive the final comprehensive assessment value.Through using the aforementioned methods,risk assessments were conducted on typical sections with instances of ballast flight within the European Union and on a ballasted track test section of China’s Yinxi High-Speed Railway.The results indicate that the risk level of routes experiencing ballast flight in the European Union from 2001 to 2010 was high,with 7 routes classified as level IV risk and 1 route as level V risk.With continuous optimization of train and track structures,the risk of ballast flight on high-speed railways gradually decreased.Particularly,the newly designed ballasted track structure of China’s Yinxi High-Speed Railway reduced ballast flight risk by optimizing the ballast gradation,canceling the height of the ballast shoulder and reducing the position of the top surface of the track bed.This method can effectively quantify factors with unclear boundaries,judge the risk level of ballast flight in high-speed railways,and guide the optimization of high-speed trains and ballasted track structures to ensure the safe operation of trains.