Analysis of Vibration Reduction Effect of the Floating Slab Track with Different Base Forms in a Small Radius Curve of Subway Lines

This paper compares the vibration characteristics of the floating slab track with different base forms and proposes a method to comparatively improve the vibration reduction effect of the "integrated assembly" construction method. Firstly, the wheel-rail force of the train passing through the small radius curve section is obtained by the dynamic simulation, and steel spring floating slabs with the flat and inclined base, tunnel models with different superelevation are established by the finite element method. Next the fundamental frequencies of slab tracks are analysed and the reaction forces of the bottom of the steel spring and the 1/3 octave vibration level of tunnel wall nodes are calculated. The results show the vibration levels of nodes of the tunnel with inclined base is larger when the train speed and the superelevation are the same, which is due to the vertical forces being applied to the different base forms of the tunnel have different vibration effects, and the larger the superelevation is, the greater the difference becomes. In view of this, we could redistribute the superelevation between the floating slab track and tunnel base instead of being completely provided by the floating slab track or tunnel base as before.