龙卷风作用下高速列车的运行安全性评估

Evaluation of the safety of high-speed trains in a tornado

随着我国铁路线网密度的加大以及龙卷风等极端天气出现的频次增多,列车遭受龙卷风袭击的风险不断增加。利用物理模拟器对列车进行测压试验,通过试验得到的气动力对龙卷风作用下高速列车的运行安全性进行评估。结果表明:受龙卷风气压降和水平风速的共同影响,列车距龙卷风中心不同相对位置时,所受风荷载作用机制明显不同;迎风侧轮轨横向力主要由侧力产生,风速较大时,升力和侧滚力矩对轮轨垂向力的贡献增大;横向力、脱轨系数、轮重减载率等列车运行安全性指标随径向距离的增大先增大后减小;列车运行安全性指标随风速、车速的增大而增大,列车安全运行的龙卷风临界风速值随车速的增大而急剧减小,其中,当车速为350km/h时,轮对横向力对应的临界风速仅为11.06m/s。

The risk of trains being hit by tornadoes continues to increase due to the increased rail network density and the increased occurrence probability of tornadoes.A series of pressure measurement tests on a train in a tornado was performed using a tornado vortex simulator,in order to evaluate the operation safety of high-speed train in a tornado.The results show that with the joint actions of tornado pressure drop and horizontal wind speed,the wind load acting mechanism shall be significantly different for different positions(or radial distances)of the train model relative to the tornado.The wheel-rail lateral force at the windward side is mainly generated by the side force,and with the increase of wind speed,the contribution of lift force and rolling moment to the wheel-rail vertical force increases.The safety indicators of train operation such as transverse force,derailment coefficient and wheel load reduction rate firstly increase and then decrease with the radial distance.The train safety operation indicators increase with the wind speed and train speed,the critical wind speed of tornado for safe train operation decreases sharply with the increase of train speed,and when the train speed is 350 km/h,the critical wind speed is only 11.06 m/s.