重载车桥耦合作用下48 m钢桁梁桥动力性能

研究目的:随着社会经济发展和人们需求的提高,铁路货运能力亟待进一步提高,在既有铁路网基础上加大铁路列车轴重是有效提高铁路运能的主要途径之一。列车轴重增大后车桥振动效应将增加,既有铁路网中的钢桥能否适应铁路轴重的提高成为列车轴重能否增加的关键问题。本文为分析重载列车作用下钢桥动力性能,选取既有线中常用跨度48 m钢桁梁桥为研究对象,通过轮对与轨道接触处的力与位移相互关系建立空间重载铁路车-桥系统耦合振动分析模型,在与实测结果对比基础上,对影响重载铁路钢桁梁桥动力性能的轨道不平顺、列车轴重和列车速度等因素进行系统分析。研究结论:(1)轨道不平顺功率谱、列车轴重和列车速度均对重载列车作用下的钢桁梁桥的动力性能有着重要影响;(2)美国六级轨道不平顺与桥上实际线路不平顺更加接近;(3)重载铁路运输中27 t轴重列车通过48 m钢桁梁桥时建议对列车运行速度进行限制。

Dynamic Response of 48 m-span Steel Truss Bridge under Heavy Haul Vehicle-bridge Coupling

Research purposes:With the development of society economy and the improvement of people’s demand,the freight capacity of railway need to be enhanced.Increasing the train axle load has become one of the main ways to improve the railway transport capacity on the basis of existing railway net.The vibration effect of vehicle and bridge will increase with the increase of axle load.Whether the steel bridge in the existing railway net can adapt the increasing axle load is the key problem in the increase of axle load.In order to analyze the dynamic performance of steel bridge under heavy haul trains,this paper selected the common span of 48 m truss steel bridge as research object.An analytical model of heavy haul vehicle-bridge system was built by combining the compatible condition of displacements and the balance relation of wheel-rail interaction forces.Based on the comparison with the experimental results,the factors such as track irregularities,train axle loads and vehicle speeds that influence the dynamic response of steel truss bridge under heavy haul trains were systematically investigated.Research conclusions:(1)The track irregularities,train axle loads and vehicle speeds all have great influence on the dynamic response of steel truss bridge.(2)The track irregularity from the sixth grade line of US is closer to the real track irregularity of the steel truss bridge than it from the fifth grade line of US.(3)During the heavy load railway transportation,the speed should be limited when the 27 t axle load train passing the 48 m-span steel truss bridge.