弹性轨枕对重载铁路有砟轨道结构受力及变形特征的影响

Influence of Elastic Sleepers on Stress and Deformation Characteristics of Ballasted Track Structure in Heavy Haul Railway

建立重载轨道结构有限元模型,分析了列车荷载作用下,不同枕下垫板刚度、不同道床厚度条件下铺设弹性轨枕对重载铁路有砟轨道结构受力及变形特征的影响,并与铺设普通轨枕地段进行了对比。结果表明:枕下垫板刚度对有砟轨道结构受力和变形特征影响较大,随着枕下垫板刚度增大,钢轨的垂向位移逐渐减小,钢轨支点反力、道床垂向位移、道床与基底的垂向应力非线性增大;对于重载铁路,枕下垫板刚度在70~100 kN/mm取值既可控制钢轨垂向位移不超过1.8 mm,又可减轻轨道部件受力、延长道床养护维修周期;道床厚度相同条件下弹性轨枕地段钢轨、道床的垂向位移大于普通轨枕地段,而钢轨支点反力、道床压应力、轨枕弯矩均有所降低,其中钢轨支点反力降低了8.6%,道床最大压应力降低了4.5%,枕中截面负弯矩降低了41.3%。

The finite element model of heavy haul track structure was established.Under train load,different stiffness of under sleeper pad and different thickness of ballast bed,the influence of laying elastic sleepers on the stress and deformation characteristics of ballasted track structure in heavy haul railway was analyzed and compared with the section with ordinary sleeper.The results show that the stiffness of under sleeper pad has a great influence on the stress and deformation characteristics of ballasted track structure.With the increase of the stiffness of under sleeper pad,the vertical displacement of the rail decreases gradually,and the rail fulcrum force,the vertical displacement of the track bed and the vertical stress of the track bed and the base increase nonlinearly.For heavy haul railway,the stiffness of under sleeper pad is 70~100 kN/mm,which can not only control the vertical displacement of the rail not more than 1.8 mm,but also reduce the stress on the track components and prolong the maintenance period of track bed.Under the condition of the same thickness of track bed,the vertical displacement of the rail and track bed in the elastic sleeper section is greater than that in the ordinary sleeper section,while the rail fulcrum force,the compressive stress of the track bed and the bending moment of the sleeper are reduced,in which the rail fulcrum force is reduced by 8.6%,the maximum compressive stress of the track bed is reduced by 4.5%,and the negative bending moment of the middle section of the sleeper is reduced by 41.3%.