Abstract:

As the traditional vibration isolation methods have no obvious effect on the low-frequency vibration,the wave-impeding block ( WIB) and the honeycomb wave-impeding block ( HWIB) are introduced in the isolation of low-frequency vibration induced by high-speed railway. In the investigation,first,a numerical model of train-subgrade is established,which simplifies the train loads as the dynamic loads moving along the subgrade. Then,the
vibrations of the ground with and without WIB and HWIB are calculated by using the finite difference software based on Lagrange algorithm. Finally,the isolation effects of WIB and HWIB are compared with those of the open trench.The results show that,for the low-frequency vibration induced by high-speed railway,the application of WIB and HWIB enables the vibration level of ground surface to reduce by 6 ~ 15 dB and 8 ~ 20 dB,respectively. Especially,for the low-frequency vibration within 10Hz,the application of HWIB can reduce the vibration amplitude by more than 80%,which means that the proposed method is effective in vibration isolation. Moreover,it is also found that HWIB is superior to the open trench with shallow embedding in terms of vibration isolation.

Key words: high-speed railway, low-frequency vibration, vibration isolation, wave-impeding block, honeycomb wave-impeding block, open trench