Abstract:Abstract:To investigate the dynamic characteristics of the tunnel-group metro station in rock site under earthquake, a large-scale shaking table test model of the structure with a scale of 1:30 was designed. The model was subjected to transverse inputs of peak accelerations of 0.07 g, 0.15 g, 0.21 g, 0.30 g, 0.50 g, 0.70 g, and 1.0 g, representing seven different intensities of artificial seismic waves.The study focused on the acceleration response characteristics, displacement response characteristics, structural damage modes, and dynamic strain response characteristics of the tunnel-group metro station under strong earthquakes. The results showed that the amplification factors curve of Arias Intensity reveals that the model rock and the hall lining structure entered into the plastic damage state after the peak acceleration of 0.5 g. The platform lining structure gradually entered into the damage state from the plastic state after the peak acceleration of 0.3 g, and the energy dissipation increases gradually. With the increase of earthquake intensity, the relative displacement of the hall cross-section increases significantly, and the gap between the peak relative displacements of the open section and the non-open section widens further. The cracks of the structure are mainly distributed in the longitudinal direction, and the longitudinal cracks in the middle of the straight wall of the platform are wide and long, while the middle of the straight wall of the hall did not produce obvious cracks. With the increase in seismic motion intensity, the main frequency of the structural transfer function gradually decreased, with the main frequencies being 22.7 Hz and 18.5 Hz in the elastic and plastic damage stages, respectively. The tensile strains at the same locations in the VL section (the lower section of the vertical connecting passage) are larger than those in the HR section (the right section that connects the horizontal connecting passage) under transverse excitations, and the maximum tensile strain occurs in the arch shoulder of the VL section.