Abstract: Subsoil vibration induced by metro train arriving at or leaving station is a special vibration with vast vibration sources. In this study, the train vibration source is simplified to the cylindrical vibration source to study vibration characteristics and different vibrations caused by metro train arriving at and leaving station. On the basis of wave theory, the wave field expression in soil space is obtained by wave function expansion method. Secondly, the reflection law is used to deduce the propagation direction of different types of reflection waves. Thirdly, according to Graf addition formula and the Bessel function transformation, the wave field expression is converted into a uniform coordinate system, and undetermined coefficients are solved by boundary conditions of large circular arc surface. Finally, according to vibration superposition in frequency domain, the wave field expression of the moving vibration source is established during the whole train arriving at or leaving the station. The validity of cylindrical vibration source calculation method is verified by comparing the theoretical calculation results of ground vibration frequency spectrum with its actual monitoring results. In addition, low-frequency vibration characteristics are more obvious when the train arriving at or leaving station. Parameteric analysis shows that both the maximum starting acceleration and initial braking speed increase with increasing the vertical vibration response.

Key words: metro subsoil, arriving at or leaving station, variable speed moving, soil space vibration, frequency spectrum analysis