Since the advent of railways, the specifications of the track system have been modified considerably. The ability of the system to absorb and reduce vibration is one of the concerns that is the main focus on the track system. Understanding the characteristics of vibrations is a decent preliminary approach to controlling the exist vibrations. In-situ experiment has been conducted on the Er Cheng Hang River Bridge. In this study, the train-induced vibration and natural frequency of the system are being examine. An One Third Octave Band-Fast Fourier transform (FFT) method is used to analyse the measurement results. The results show there are two prominent frequencies of each train caused by very likely the induction of train speed. The 63 Hz found as the natural frequency of the bridge and this peak is validated by the analysis of vibration before it totally disappears. It was also found 100 Hz and 630 Hz are the natural frequencies of the track system and it is validated by conducting the instrumented sledgehammer test. The Elastic Base Plate indicate to reduce the vibration around 30 – 40 dB.

REFERENCES
Bian, X., Jiang, H., Chang, C., Hu, J., &Chen, Y. (2015). Track and ground vibrations generated by high-speed train running on ballastless railway with excitation of vertical track irregularities. Soil Dynamics and Earthquake Engineering, 76, 29–43. https://doi.org/10.1016/j.soildyn.2015.02.009
Chen, R. J. T., Wang, T., Chang, K., &Chang, S. (n.d.). Taiwan Trackwork Development-Nonballast Track System-.
Degrande, G., Schevenels, M., Chatterjee, P., Van deVelde, W., Hölscher, P., Hopman, V., Wang, A., &Dadkah, N. (2006). Vibrations due to a test train at variable speeds in a deep bored tunnel embedded in London clay. Journal of Sound and Vibration, 293(3–5), 626–644. https://doi.org/10.1016/j.jsv.2005.08.039
Ju, S. H., Lin, H. T., &Chen, T. K. (2007). Studying characteristics of train-induced ground vibrations adjacent to an elevated railway by field experiments. Journal of Geotechnical and Geoenvironmental Engineering, 133(10), 1302–1307. https://doi.org/10.1061/(ASCE)1090-0241(2007)133:10(1302)
Melke, J., &Kramer, S. (1983). Diagnostic methods in the control of railway noise and vibration. Journal of Sound and Vibration, 87(2), 377–386. https://doi.org/10.1016/0022-460X(83)90577-1
Ono, K., &Yamada, M. (1989). Analysis of railway track vibration. Sound and Vibration, 130(2), 269–297.
Yang, N., Guo, T., &Sun, G. Z. (2013). Train-induced vibration on elevated railway station. Journal of Central South University, 20(12), 3745–3753.
https://doi.org/10.1007/s11771-013-1903-2
Zhang, X., Li, X., Song, L., Su, B., &Li, Y. (2016). Vibrational and acoustical performance of concrete box-section bridges subjected to train wheel-rail excitation: Field test and numerical analysis. Noise Control Engineering Journal, 64(2), 217–229. https://doi.org/10.3397/1/376373
Pyrgidis, C. (2016). Railway Transportation Systems. Boca Raton: CRC Press, https://doi.org/10.1201/b19472