Research On The Vertical Vibration Transmissibility Of Steel Spring Floating Slab Track Structure On The 32m Simply Supported Box Beam

In the three installation methods of subway lines, elevated line became the form of urban rail lines of the construction and design department concerned because its small input in construction and less operational and maintenance expenses. However, due to the direct exposure in the environment, the vibration and acoustic noise of urban rail bridge directly affect and radiate into the environment, and brought environment vibration and noise pollution problems. How to control the vibration and noise problems of the urban rail bridge and suggest some vibration and noise reduction methods has already become a problem badly in need of solution.As a new effective damping track structure, floating slab track structure has been widely used in many countries and regions, and have achieved great success in the vibration isolation and noise reduction.The study on this paper is mainly about the vertical vibration transmissibility of steel spring floating slab track structure on the 32m simply supported box beam from the perspective of frequency domain analysis, This paper establishes a 3D finite element model of steel spring floating slab on bridge. The model considers the interaction of the bridge, the floating slab and the rail, So it can imitate the vertical vibration transmissibility of steel spring floating slab track structure on bridge accurately.This paper analyzes the dynamic response of various parts of floating slab track on bridge under the 1-500Hz excitation frequency from the aspects of frequency domain, including the receptance of rail, floating slab, bridge and Transmit force admittance and so on. The influence of different length of floating slab and structural parameters affects over the vibration of various parts of the structure is analysed in this paper, and the paper provides the theories reference for the vibration-decreasing measures of floating slab track structure on bridge.On the basis of the previous research, this paper makes a thorough study of the vertical vibration transmissibility of steel spring floating slab track structure on bridge, and some results are obtained:Compare with the ballastless track, floating slab track can greatly reduce the vibration transferred to the bridge, at low frequencies, the rail and floating slab vibration of floating slab track is higher than the vibration of ballastless track; the flexural wave increases with the increase of the length of floating slab, and more vibration will return to rail. The influence of Stiffness of steel spring on vibration isolation effect is obvious, the vibration isolation effect of steel spring floating slab track structure on the bridge can be increased by reducing the stiffness of steel spring. the vibration at resonant frequency of floating slab track can be reduced effectively by increasing the damping of steel spring.