2.2. Track system modelThe track structure analyzed in this study was the DPFS. The fastener of the DPFS is supported by the track slab, and the track slab issupported by the rubber damping pad. The track slab is made of cast-inplace concrete, comprising two parts (the track-supporting block andbase plate), and it is disconnected at regular intervals. As shown inFig. 4, the static stiffness of the damping pad is expressed as Kd, and thethickness as Hd. Fig. 4(a) shows an image of the rubber damping pad.For the convenience of analysis, the damping pad is simplified assupporting springs.