Dynamic response study of an underground large-span station transportation hub

Abstract With the rapid urbanization in China, underground transportation hubs have become critical nodes in urban lifeline systems, yet the dynamic response mechanisms of large-span structures under seismic loads remain poorly understood, particularly in complex soil-structure interaction scenarios. This study experimentally investigates the dynamic response characteristics of an underground large-span station transportation hub through physical modeling. The experimental results show that the seismic response is more sensitive for the lower and upper floors, while in the cross-traversal region in the middle floors, the peak acceleration of the structure shows some slow increase characteristics. The peak acceleration of the soil body in the vertical direction shows significant nonlinear fluctuation characteristics, which is specifically manifested as with the increase of the height from the bottom of the box, the peak acceleration first increases to a local maximum, then decreases, and finally in the area near the top again shows a weak rebound, and the overall formation of a three-stage evolution trend.