Seismic Safety and Post-Earthquake Resilience of Frame with Debonded High-Strength Reinforced Concrete-Encased-and-Filled Steel Tubular Columns

The incremental dynamic analysis of a ten-floor frame archetype whose concrete encased-and-filled steel tubular (CEFST) columns with debonded high-strength reinforcements (DHSRs) was performed. Seismic fragility results showed the use of DHSR is beneficial for the seismic safety of CEFST frame system, especially for the prevention of seismic collapse. The utilization of CEFST columns with DHSRs in the first three stories alone introduced a small probability of seismic damage. The fragility curves of residual story lateral drifts indicated the use of DHSR can significantly mitigate the residual deformation. Precise evaluation of residual drift of frame structure should be further studied.

Automated summary

This study conducted an incremental dynamic analysis of a ten-floor frame prototype with concrete encased-and-filled steel tubular (CEFST) columns and debonded high-strength reinforcements (DHSRs). The results of seismic fragility analysis showed that the use of DHSRs is beneficial for the seismic safety of the CEFST frame system, particularly in preventing seismic collapse. Additionally, the utilization of DHSRs significantly mitigated the residual deformation of the frame structure. However, further research is needed to accurately evaluate the residual drift of the frame structure.