1.State Key Laboratory of Disaster Reduction in Civil Engineering/ Department of Disaster Mitigation for Structures, Tongji University, Shanghai 200092, China;

2. Guangzhou Municipal Industry and Information Technology Bureau, Guangzhou, Guangdong 510032, China

To assess the performance of seismically isolated staircases in self-centering frame structures, a four-story controlled rocking reinforced concrete frame (CR-RCF) is chosen for analysis. Finite element models of the frames are created, featuring staircases with different designs. The dynamic responses of these models are compared under both frequent and rare seismic events. The findings revealed that during frequent earthquakes, the maximum inter-story drift ratio for models with sliding staircases and rubber bearing staircases are about twice that of the fixed staircase model. However, the base shears are decreased by 37% and 43%, respectively. In the case of rare earthquakes, the base shear reductions are reduced by 45% and 34% for the sliding and rubber bearing staircases, highlighting their effectiveness in reducing the structure's dynamic response. Additionally, during rare seismic events, the maximum inter-story drift ratio for the rubber bearing staircase are two to three times higher than that of the fixed staircase, while the maximum sliding displacement is significantly below design limit, confirming its safety and reliability in extreme seismic situations. This research offers an initial investigation on the selection of staircases in self-centering frame structures, demonstrating that both rubber bearing staircases and sliding staircases are suitable for these types of structures, effectively safeguarding the main structure from severe damage and improving the overall seismic performance and safety of the building. Consequently, it is advised to prioritize rubber bearing staircases or sliding staircases in the design of self-centering frame structures to enhance their seismic safety.

self-centering structure; isolated stairs; finite element analysis; dynamic time-history analysis