Research conclusions：By means of establishing models of the vehicle—track—roadbed—ground coupling system and the ground—barrier coupling system．the studies have been done on the vibration isolation effects of five barriers，i．e．， open trench，in—filled trench，stiff trench，piles and three—rOWS of honeycomb WIB，with the universal finite— element software ANSYS．The results show that 1 5 dB vibration can be reduced by using three—rOWS of the honeycomb WIB，reducing6—8dB vibration by open trench and reducing 5 dB vibration by in—filled trench，stiff trench and three—rOWS of the piles respectively．