Analysis on Displacement‐based Seismic Design Method of Recycled Aggregate Concrete‐filled Square Steel Tube Frame Structures

Recycled aggregate concrete-filled square steel tube (S-RACFST) frame has the characteristics of high bearing capacity, good ductility, and superior seismic performance. To propose a displacement-based seismic design of S-RACFST frame, the validity of the design method was verified by a detailed calculation example. Based on the performance requirements, this design method divided the structural performance into five levels: normal use, temporary use, use after strengthening, life safety, and collapse prevention, and suggested specific steps for the displacement-based seismic design of S-RACFST frame using the inter-story displacement angle limit value as the quantitative indicator. The 10-story S-RACFST frame was used as an analytical example for static elastic-plastic analysis. The pushover lateral displacement curves of the frame structure at each performance level were obtained and compared with the displacement-based seismic design curves. The results show that the displacement-based seismic design method of S-RACFST frame structures can fulfill the performance level requirements such as "temporary use, " "normal use, " and "collapse prevention, " and the displacement-based seismic design method is one of the effective ways to realize the performance design of S-RACFST frame structures.