160 km/h市域铁路装配式浮置板轨道研究

Study on assembled floating slab track of 160 km/h municipal railway

针对时速160 km,17 t轴重条件下的市域铁路,提出一种在板缝处设置剪力铰和隔振器的装配式长型钢弹簧浮置板轨道。为验证该轨道结构对市域快线行车的适应性,建立三维车辆-轨道-基础耦合动力学模型,分析160 km/h速度下车辆和轨道结构的动力学响应,并对板缝结构、隔振器合理刚度以及减振效果进行研究。研究结果表明:在板缝处设置隔振器可以有效减小板端的钢轨位移、浮置板位移以及板中的隔振器反力,设置剪力铰可以有效减小浮置板板端的振动加速度和相对错动。在板缝处同时设置隔振器和剪力铰可以加强装配式浮置板轨道的薄弱环节,使整体的受力和变形更加均匀;隔振器间距取2.4 m且刚度在7.5~25 kN/mm范围内时,隔振器刚度变化对车体动力响应的影响较小,车体各项动力指标均满足规范的要求,但隔振器刚度小于15 kN/mm时钢轨最大位移会超过规范限值,此时车辆运行的安全性不能得到保证;本结构设计参数下的浮置板轨道减振效果可达15 dB以上,且在高频段的减振较为明显。隔振器刚度由7.5 kN/mm增大到25 kN/mm后,减振效果由26.29 dB减少至15.32 dB。综合考虑车体动力响应、轨道位移限值以及减振效果,建议本设计的装配式浮置板轨道的隔振器刚度取15 kN/mm。

For the municipal railway with 160 km/h and 17 t axle load,a fabricated long steel spring floating slab track with shear hinge and vibration isolator at the slab joint was proposed.In order to verify the adaptability of the track structure to the urban expressway,a three-dimensional vehicle track foundation coupling dynamic model was established.The dynamic response of the vehicle and track structure at the speed of 160 km/h was analyzed,and the slab joint structure,the reasonable stiffness of the vibration isolator and the vibration reduction effect were studied.The results show that the setting of vibration isolator at the slab joint can effectively reduce the rail displacement at the slab end,the displacement of floating slab and the reaction force of vibration isolator in the slab,and the setting of shear hinge can effectively reduce the vibration acceleration and relative dislocation at the slab end of floating slab.Setting vibration isolators and shear hinges at the slab joints can strengthen the weak links of the fabricated floating slab track and make the overall stress and deformation more uniform.When the spacing of vibration isolators is 2.4 m and the stiffness is within the range of 7.5~25 kN/mm,the stiffness change of vibration isolators has little impact on the dynamic response of the vehicle body,and all dynamic indices of the vehicle body satisfy the requirements of the specification.However,when the stiffness of vibration isolators is less than 15 kN/mm,the maximum displacement of steel rail exceeds the specification limit,and the safety of vehicle operation cannot be guaranteed.The vibration reduction effect of the floating slab track under the structural design parameters can reach more than 15 dB,and the vibration reduction is obvious in the high frequency band.After the stiffness of the vibration isolator is increased from 7.5 kN/mm to 25 kN/mm,the vibration reduction effect is reduced from 26.29 dB to 15.32 dB.By considering the vehicle body dynamic response,track displacement limit and vibration reduction effect,it is suggested that the vibration isolator stiffness of the fabricated floating slab track in this design is 15 kN/mm.