摘要
路基动应力特性在高铁路基设计中非常重要,因此对其进行研究具有一定的意义。通过列车-轨道-路基三维有限元数值方法,计算得到了在京津城际轨道不平顺谱下路基面横向各位置处的动应力。利用概率统计理论,统计得到了3种列车速度下路基面横向各位置处动应力的均值和变异系数;并通过对路基面中心位置处动应力计算结果进行统计分析得到了京津城际轨道不平顺谱下路基动应力的最优概率分布模型。结果表明,在京津城际轨道不平顺谱下,路基面动应力均值沿横向呈现"M"型分布,变异系数沿横向逐渐减小。列车速度对路基动应力均值及变异系数具有一定的放大效应,且路基动应力沿纵向近似服从对数正态分布。
This paper intends to provide its analysis of the probabilistic characteristic features of the dynamic stress of the highspeed railway subgrade surface of Beijing-Tianjin inter-city communal railway in the broadwise direction of 6 nodes and in the longitudinal direction of 321 nodes of the subgrade surface under the track irregularity spectrum.According to the vehicle-tracksubgrade dimensional finite element model,there can be found three typical high-speed railway driving speeds,known as 150 km/h,250 km/h and 350 km/h.However,based on the reliability theory and the probability statistics theory,the mean value and coefficients of the variations(COVs) of the dynamic stress of subgrade in the said direction can be gained by calculating the dynamic stress of the subgrade in the aforementioned situations.And,finally,we have worked out the mean values and the coefficient of variations(COVs) of the dynamic stress of the subgrade in the broadwise direction of the subgrade surface through comparison of the probability distribution of the dynamic stress of the subgrade in the central position of subgrade surface and the histogram of the data predicted of log-normal distribution,with the mean data and the standard deviation being given.And,in turn,we have proved and proposed the optimized probability distribution model for assessing and forecasting the dynamic stress of the subgrade under the said track irregularity spectrum.Thus,from what is said above,it can be concluded that the above mentioned dynamic stress of the subgrade should be random by nature for the track irregularity.The distribution for the mean values of dynamic stress of subgrade in the broadwise direction on the subgrade surface is supposed to be approximately of a letter"M"type,whereas the distribution of the COVs of the dynamic stress of subgrade surface should be gradually decreasing in the broadwise direction under the above mentioned irregularity spectrum.Besides,the train moving speed should have noticeable impact on the mean values and the COVs of the dynamic stress of the subgrade.And,conclusively speaking,the distribution of the dynamic stress of the subgrade in the longitudinal direction should be approximate to the log-normal distribution under the said track irregularity spectrum.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2016年第3期150-153,共4页
Journal of Safety and Environment
关键词
安全工程
路基动应力
京津城际轨道
不平顺谱
均值
变异系数
对数正态分布
safety engineering
dynamic stress of subgrade
Beijing-Tianjin inter-city track
irregularity spectrum
mean value
coefficient of variation(COV)
lognormal distribution