Comparative Experimental Analysis of the Vibration Mitigation Characteristics of Ballast Track Using New Rubber Composite Sleeper and Concrete Sleeper

Modern rail transportation development necessitates the development of improved new materials and methodologies for analysing the vibrations of railway tracks. These vibrations occur because of extreme loading /impact load conditions due to the train operations with either wheel or rail eccentricity(such as flat wheels, dipped rails). The impact loads are irregular and powerful but have a brief duration over time, resulting in track deterioration and severe environmental influences. This paper used a full-scale laboratory model with eight different kinds of sleepers to measure the vibration reduction characteristics of the ballasted track with new rubber composite sleepers (RCSs) and compared them to those of the ballasted track with concrete sleepers (CSs); before using them in-situ railway system. A high-capacity drop hammer impact test was used to achieve this purpose, and the vibration responses of the track components were analysed in both time and frequency domains. Two cases were taken to investigate the vibration of the railway ballast track. A series of vertical height (VH) impact tests for both sleepers were carried out ranging from 50mm, 100 mm, and 150 mm drop hammer height to investigate its natural frequency and vibration reduction. The results show that the RCSs can reduce the peak acceleration and root-mean-square (RMS) distribution of track component ballast and ground better than the track with CSs in both lateral and longitudinal directions. Therefore, more vibration attenuation amplitude and power/energy capacity are improved, respectively. The time and frequency domain analysis along the lateral and vertical lines of the track showed that the track with RCSs has lower vibration acceleration peaks, fewer frequency peaks, decreased velocity, and shorter vibration cycles than the track with CSs. The track with RCSs significantly lowered/reduced vibration levels of the ballasted track by -5.04 dB, 1.71 dB, and -2.46 dB for the rails, sleepers, and ballast, respectively, of case one and 11.77 dB of the ballast in case two. Furthermore, the RCSs can reduce the vertical acceleration level (VAL) of the ground by 18.6 dB and 14.3 dB for points in the same line with sleepers, and 3.9 dB and 7.5 dB for points parallel to the ballast as compared with track with CSs; approximately similar to the result observed in case two of the experiment. Therefore, the ballasted track with RCSs substantially influences the ballast and ground in terms of vibration reduction.