Laboratory Vibration Studies of Metro Tracks Equipped with Tuned Rail Dampers

Purpose: With the rapid development of urban metro systems in the growing cities of China, a way to reduce metro train-induced track vibrations transmitted through ground to surrounding buildings has attracted the attention of engineering researchers. Using additional mass, damping and flexural stiffness to improve the dynamic performance of metro tracks, a Tuned Rail Damper (TRD) is developed to mitigate the vibrations of the metro tracks. Methods: In this paper, a laboratory hammer test is designed and carried out to assess the vibration performance of a 3-interval (of 3 × 0.6 m) metro track installed with the TRD sets. Results: The hammer test results indicated that depending on the position of a hammer impulse acting on the 3-interval track unit, different excitation frequencies would be measured. Conclusion: According to the experimental study, the TRD has advantages such as easy installation, convenient inspection by hammer test, and good vibration reduction performance for its flexural strengthening effect on metro tracks. Moreover, the composed TRD-track system has a robust ability to reduce vibrations and an increase of higher frequencies compared to conventional tracks. This dynamic feature can decrease the risk of clip failure in a fastening system subjected to intensive excitations from moving metro trains.