Prediction of ground-borne vibration induced by a moving underground train based on excitation experiments

The accurate prediction of ground-borne vibration induced by underground trains is needed to assess the effects of vibration. However, there are inaccuracy and uncertainty for current empirical and numerical approaches due to theoretical assumptions, simplifying modeling and uncertainty of parameters. To reduce the inaccuracy and uncertainty, this paper presents a prediction strategy based on the transfer function experiment in a borehole or tunnel. The frequencydomain dynamic response in the ground can be determined from the excitation forces applied on the tunnel invert and the transfer functions in the experiment. A vehicle-track model is established to obtain the excitation forces, and the transfer functions are measured in the hammer impact experiments in a borehole or tunnel. Validation of this approach is provided by comparison to the measured response on a metro line in Beijing. It is shown that more accurate prediction can be expected by this approach as the actual transfer characteristics of vibration in the ground are measured.