ANALYSIS ON THE REASONS OF GROUND VIBRATION AMPLIFICATION INDUCED BY RAILWAY TRAFFIC

To study the reasons which cause the ground vibration amplification induced by railway traffic, the propagation laws of ground vibration responses for each frequency are analyzed with the help of both the drop-weight test and analytical solution of a displacement Green’s function in a halfspace. The conditions include that the vibration source are on the surface and underground. Results show that: 1) when the vibration source applies on the surface, the ground vibration of each frequency attenuates with a fluctuation. There is an interval of fluctuation, which has the relationship with its frequency. Due to the difference of attenuation speeds of body wave and Rayleigh wave, the superposition of the two kinds of the waves mainly induce the phenomenon of fluctuant attenuation. 2) When the vibration source applies underground, there is an obvious wave crest or trough in an adjacent field, whose location is related to the embedded depth of source. In a far field, the similar fluctuant attenuation with the first condition can be found.