地震作用下列车过桥安全性分析

通过建立的地震荷载作用下车桥系统动力响应分析模型,对不同的高速列车在典型地震荷载作用下通过秦沈客运专线上多跨双线简支箱梁桥的全过程进行了仿真分析,对影响地震发生时高速铁路常用跨度简支梁桥动力响应行为和车辆运行安全的主要因素进行了分析和研究,其结果表明增大桥梁结构的阻尼比可有效改善桥梁本身的抗震性能,但对提高列车在地震时过桥的安全性意义不大;地震作用使车体的横向振动加速度以及脱轨系数、轮重减载率和横向轮轨力等各项安全评价指标均随列车速度的提高而增大,因此,在评价地震作用下高速铁路简支梁桥上列车的走行安全性时,必须考虑列车运行速度的影响;给出了确保地震发生时高速列车在桥上安全运行的临界速度限值。

Running Safety Analysis of Trains Passing over Bridge during Earthquake

A dynamic model of train-bridge system under earthquake is established. By computer simulation, the whole histories of different trains running on the multi-span bridge with simple-supported PC box girders cartying double tracks of Qinhuangdao-Shenyang Special Passenger Railway in China are simulated, and the dynarnic responses of the bridge and the trains are calculated. The running safety parameters of train-bridge system are studied in detail. The results show that increasing damping ratio could improve the bridge itseLf the anti-seismic performance effectively, however, it is riot significant in ensuring the running safety of the trains when passing the bridge enduring earthquake. The dynamic response of train vehicles including the lateral car body accelerations and the safety evaluation indexes all increase with the train speed, so the influences of train speed must be taken into account in evaluating the running ability of vehicles on the bridge during earthquake. The critical safety speed limits of train passing over the bridge subjected to earthquakes are proposed.