基于可靠度理论的桥上列车横风安全性分析

Crosswind safety analysis for atrain running on abridge based on reliability theory

基于可靠度理论,分析风荷载作用下高速列车在桥上的运行安全性,利用失效概率来评价桥上列车横风安全性。首先由风洞试验获得的列车和桥梁的气动力系数,计算列车和桥上的气动力,然后建立风荷载作用下车桥耦合系统分析模型,计算不同平均风速下高速列车以不同车速在桥上运行时的安全性评价指标,最后基于可靠度理论计算高速列车桥上运行的失效概率。以兰新铁路第二双线上的十跨简支槽型梁桥为例,分析横风作用下高速列车桥上运行时的失效概率,并与确定性分析方法比较,结果表明:随着列车运行速度和平均风速的增加,车桥系统的失效概率增加;相同车速及平均风速时,拖车比动车的失效概率大;采用确定性方法获得的列车特征风曲线,对动车其大致与失效概率10%的列车概率特征风曲线相当,对拖车则对应着更低的失效概率。

Based on the theory of reliability,the running safety of a high-speed train on a bridge under wind loadswas analyzed,and the failure probability was used to evaluate the crosswind safety of the train on the bridge.Firstly,aerodynamic coefficients of the train and bridge obtained withwind tunnel testswereused to calculate aerodynamic forces acting on the train and the bridge.Then,the analysis model for the train-bridge coupled system under wind loadswas established,and safety evaluation indices for the train running on the bridgeat different velocitieswere calculated under different average wind speeds.Finally,the failure probability of the high speed train running on the bridgewas calculated based on the reliability theory.A 10-span simply-supported U-shape girder bridge of Lanxin Railway was taken as an example to analyze the failure probability of the high speed train running on the bridge under crosswind.The results were compared with those using the deterministic analysis method.The results showed that with increase in train running velocity and average wind speed,the failure probability of the train-bridge coupled system increases;failure probability of trail-car is larger than that of motor-car at the same train running velocity and average wind speed;the train characteristic wind curve for motor-carobtained with the deterministic methodis roughly equivalent to theprobabilistic characteristic wind curve of the train with failure probability of 0.1,whilethat for trail-car is corresponding to one with lower failure probability.