Efficient time-frequency approach for prediction of subway train-induced tunnel and ground vibrations

In this paper, an efficient time-frequency approach is presented for the prediction of subway train-induced tunnel and ground vibrations. The proposed approach involves two steps. In the first step, a time domain simulation of the vehicle-track subsystem is used to determine the track-tunnel interaction forces and, in the second step, the resulting forces are then applied to a 2.5 D FEM-PML model of the tunnel-soil system. There are two main aspects to the novelty and contribution of this work: First, the errors of the linearized Hertzian wheel-rail contact models in the calculation of the track-tunnel interaction forces are quantified by a comparison with the nonlinear Hertzian contact model. The results show that the relative errors are less than 2%. Second, an efficient time-frequency analysis framework is proposed, including the use of a strongly coupled model in the time domain solution and a 2.5 D FEM-PML model in the frequency-wavenumber domain solution. Finally, the accuracy and efficiency of the proposed approach are verified by comparison with a time-dependent 3 D approach, where three types of soil, i.e. soft, medium, and hard, are considered.

Automated summary

An efficient time-frequency approach is proposed for predicting subway train-induced tunnel and ground vibrations. The novelty and contribution of this work lie in quantifying errors of linearized Hertzian contact models and proposing an efficient time-frequency analysis framework. The proposed approach is verified to be accurate and efficient through comparison with a time-dependent 3D approach.