Mechanical response characteristics of railway tunnels under train loading

This study focuses on the mechanical response characteristics of railway tunnels under train loading, which is investigated in depth through model tests. The design of the test covers the similarity ratio, model box, structural model, transducer and loading condition, etc. The model test process includes shaker fixing and model box filling. The test results show that: (1) under different loading frequencies, the acceleration at each measurement point of the tunnel lining cross-section is sinusoidal, which is positively correlated with the frequency, and there is a good third-order polynomial fitting relationship between the loading frequency and the peak acceleration. (2) The peak acceleration of the vault and the left arch foot varies significantly under specific frequency conditions, and the peak acceleration of the superelevation arch grows rapidly; (3) The pattern of change of peak acceleration in the time domain analysis is highly consistent with the pattern of change of amplitude in the corresponding frequency domain analysis. This study provides important data support and theoretical basis for the design, construction and maintenance of railway tunnels, which helps to ensure the safe operation of railway tunnels, and at the same time provides a reference for further in-depth research on the evolution of the performance of the tunnel structure under the action of complex train loads.