Investigations on Seismic Response of Existing Building Systems When New Tunnels Constructed with Varying Buried Depths

During the development of urban underground space, interactions between existing building systems and newly constructed tunnels through the surrounding soil generate coupled effects. Understanding their seismic response is therefore crucial for earthquake-resistant design and risk assessment. Given the coexistence of newly constructed tunnels and existing buildings at the same site, this study examines the seismic response of building systems under varying tunnel burial depths. Using a real engineering case, a combined methodology of shaking table model tests and numerical simulations is adopted to analyze how tunnel depth affects the seismic performance of the building system. The results indicate that the presence of a new tunnel reduce the seismic response of existing building systems. The response of the existing building system decreases first, and then increases with the increase of tunnel depth.When the burial depth of the new tunnel is three times its diameter (3D), the impact on the seismic response of existing building systems is most unfavorable. The research findings can provide valuable reference for the selection in actual projects.