|
This paper proposes a track-tunnel-unsaturated soil model for predicting the vibrations induced by the urban underground rail transit. The track structure subsystem and tunnel-unsaturated soil subsystem were coupled by the force between the slab and tunnel invert. Firstly, the radial displacement frequency response function (FRF) at the tunnel invert was calculated. Then, the coupled equations of rail, slab and tunnel were used to obtain the interaction force between slab and tunnel. Finally, other dynamic response could be calculated by multiply the interaction force by the corresponding FRF. After being validated via comparison with existing saturated soil model, the present model was applied to investigate the effects of water saturation, speed and frequency of train load on the dynamic response of the system. The results show that the radial displacement at tunnel invert is increase with the increase of water saturation. The matric suction amplitudes decrease first and then increases with the increase of water saturation.
|
