极端温度下高速铁路钢管混凝土拱桥行车安全

Running Safety of High-speed Railway Concrete-filled Steel Tube Arch Bridge under Extreme Temperature

研究目的:为研究温度荷载作用下桥梁结构产生的变形对桥上行车安全性的影响,以成贵高铁某钢管混凝土拱桥为研究对象,基于ANSYS建立大跨桥梁-轨道精细化有限元模型,分析不同温度荷载作用下结构变形规律。在此基础上,将桥梁-轨道结构有限元模型导入SIMPACK中进行联合仿真,构建列车-轨道-桥梁耦合振动分析模型,最后从列车运营安全性与舒适性方面讨论不同温度荷载作用和不同车速下列车动力响应指标的变化规律。研究结论:(1)桥梁上挠温致变形引起的轨道附加不平顺比下挠更不利;(2)组合温度作用下,行车安全性指标仅轮重减载率出现超限,建议将其作为高速铁路桥上行车安全的主要评价指标;(3)温度梯度是导致轮重减载率出现超限的重要原因,实际工程中分析温度作用对列车行车安全的影响时,应考虑温度梯度的作用;(4)垂向Sperling指标对温度作用十分敏感,为保障行车舒适性,列车在极端温度条件下行驶时应控制车速;(5)本研究成果可为钢管混凝土拱桥的行车安全性评价提供参考。

Research purposes:In order to study the influence of the deformation of bridge structure under temperature load on the running safety on the bridge,taking a concrete-filled steel tube arch bridge of Chengzhou-Guizhou high-speed railway as the research object,a refined finite element model of long-span bridge-track is established based on ANSYS,and the deformation law of structure under the action of different temperature load is analyzed.On this basis,the finite element model of bridge-track structure is imported into SIMPACK for co-simulation,and the train-track-bridge coupling vibration analysis model is established.Finally,the variation rules of dynamic response indexes under different temperature loads and different speed are discussed from the aspects of train operation safety and comfort.Research conclusions:(1)The additional track irregularity caused by the upward deformation of the bridge is more unfavorable than the downward.(2)Under the effect of combined temperature,only wheel load reduction rate exceeds the limit of driving safety index,which is suggested to be taken as the main evaluation standard of running safety for high-speed railway.(3)Temperature gradient is an important reason for wheel load reduction rate exceeding the limit,and the effect of temperature gradient should be considered when analyzing the effect of temperature on train running safety in practical engineering.(4)The vertical Sperling index is very sensitive to the effect of temperature,and in order to ensure driving comfort,the speed of the train should be controlled when running under extreme temperature conditions.(5)The research results can provide reference for the driving safety evaluation of concrete-filled steel tube arch bridge.