枕下支撑刚度对轨枕性能影响分析

城市轨道交通线路通车运营后碎石道床发生不均匀沉降,枕下支撑刚度发生变化,导致轨枕病害的产生,无法有效保持轨道形位和纵横向阻力,需要深入研究轨枕下支撑刚度对其性能的影响,以便更好地治理轨枕病害问题。采用不同枕下支撑刚度对轨枕的支撑作用模拟碎石道床不均匀沉降,建立有限元模型进行受力计算,分析不同支撑刚度对轨枕变形及弯矩等性能的影响。结果表明,轨枕跨中支撑刚度越大,轨枕变形和受力越小,但轨枕跨中弯矩相应增大;轨枕跨中支撑刚度变小时,轨枕变形增加。由此可见,轨枕跨中若出现道砟缺失,引起轨枕空吊,枕下支撑刚度减小,则轨枕处将产生较大变形,相邻的轨枕也将承受较大的荷载,严重时造成轨枕失效。

Analysis of impact of support stiffness under sleeper on sleeper performance

The uneven settlement of the ballast bed and the change of the support stiffness under the sleeper lead to the occurrence of sleeper diseases,which fails to maintain the track shape and vertical and horizontal resistance effectively.It is necessary to study the influence of the support stiffness under the sleeper on its performance in order to better control the sleeper defects.The supporting effect of different support stiffness under sleeper on sleeper is used to simulate the uneven settlement of ballast bed,and the finite element model is established to calculate the stress,and the influence of different support stiffness on the deformation and bending moment of sleeper is analyzed.The results show that the bigger the rigidity of the mid span support,the smaller the deformation and stress of the sleeper,but the bigger the mid span bending moment,and the smaller the rigidity of the mid span support,the bigger the deformation of the sleeper.It can be seen that if there is a lack of ballast in the middle of the sleeper span,resulting in the empty lifting of the sleeper and the reduction of the rigidity of the support under the sleeper,the sleeper will have a big deformation,and the adjacent sleepers will also bear a heavy load,causing the sleeper failure in serious cases.