Abstract
In this study, we calculated with FEM analysis the changes in the frequency response of the vibration of the ballast layer and road bed due to application of the resilient sleeper in the frequency range of less than 200 Hz, which has a big influence on the ballast settlement. The results show that the use of the under sleeper pads (USP) with less than 0.23 N/mm3 of bedding modulus decreases the natural frequencies and the peak values of two modes: the one in which the sleepers and the ballast layer vibrate with the equal phase and the other in which they vibrate with the opposite phase. These changes lead to a vibration reduction of the ballast and road bed in the frequency band including these modes. Furthermore, we measured the road bed acceleration during a train passing in the section equipped with the resilient sleepers, and confirmed the reduction of the road bed acceleration by 3-8 dB in the frequency band of 60-150 Hz including the opposite phase mode.
