基于Monte Carlo高速铁路飞砟可靠性分析研究

Reliability assessment on high speed railway ballast flight based on monte carlo

飞砟现象是影响高速有砟道床应用和发展核心问题之一,飞砟具有随机性、离散性和复杂性等特点。基于高速铁路飞砟力学极限状态方程,综合考虑飞砟颗粒所处空气动力流场和道床及其振动不确定性因素,运用Monte Carlo模拟方法对各种不确定性因素进行定量分析,根据飞砟风险可靠度指标,初步对飞砟发生概率进行量化分析和风险评估。研究结果表明,随着道砟表面平均风速、风荷载负压力系数和道床振动所致的道砟加速度的增大,飞砟发生概率逐渐增大;随着道砟质量和道砟颗粒间咬合力增大,飞砟发生概率逐渐降低。飞砟发生概率风荷载影响敏感较强,有必要对高速铁路有砟道床进行空气动力学分析,如有砟道床断面及砟肩选型优化来抑制飞砟现象的发生。

Ballast flight is a key problem influencing the application and development of ballasted high speedtrack, which is of random, discrete and complex nature. In the paper, based on ballast flight limit state function,the Monte Carlo simulation method was used to quantify the uncertain factors, including the dynamic ballast bedand aerodynamic effects. The quantitative probability of occurrence and risk assessment for ballast flight were investigated.The results show that the occurrence probability increases with mean wind velocity, wind pressure coefficientsand the acceleration induced by track bed vibration, and decreases with the ballast mass and particleinterlock force. The ballast flight reliability is sensitively influenced by aerodynamic effects, and the HSR ballastbed need aerodynamic optimization, such as ballast bed cross section and shoulder ballast design optimization toreduce the risk of ballast flight.