ABSTRACT
For the Suburban Railway with 160km/h and 17t axle load, a fabricated long steel spring floating slab track with shear hinge and vibration isolator at the slab joint is proposed. In order to verify the adaptability of the track structure to the urban expressway, a vehicle-track-foundation coupling dynamic model is built, the dynamic response of the vehicle and track structure at the speed of 160km/h is analyzed, and the joint slab structure of the reasonable stiffness of the vibration isolator and the vibration reduction effect is studied. The results show that setting the vibration isolator and shear hinges at the slab joints can effectively reduce the displacement, vibration acceleration, relative dislocation, and the reaction force of the vibration isolator in the slab and strengthen the weak links of fabricated floating slab track. The spacing of vibration isolators is 2.4m. When the spacing of the vibration isolator is 2.4m, and the stiffness is within the range of 7.5~25kN/mm, the dynamic response of the vehicle body meets the requirements of the specification, but when the stiffness of the vibration isolator is less than 15kN/mm, the maximum displacement of rail will exceed the limit of the specification. The vibration reduction effect of the floating slab track under the structural design parameters can reach more than 15dB, and the vibration reduction is obvious in the high-frequency band. After the stiffness of the vibration isolator is increased from 7.5kN/mm to 25kN/mm, the vibration reduction effect is reduced from 26.29dB to 15.32 dB. Considering the vehicle body dynamic response, track displacement limit, and vibration reduction effect, it is suggested that the stiffness of the vibration isolator of the fabricated floating slab track in this design is 15kN/mm.
