Seismic behaviour of prefabricated square reinforced concrete-filled steel tubular pier with a grouting sleeve connection

This study developed a prefabricated square reinforced concrete-filled steel tubular (PRCFST) pier with a grouting sleeve connection. The seismic performance of the developed pier is investigated by quasi-static testing and finite element analysis (FEA). A restoring force model for the PRCFST pier with a grouting sleeve connection is developed to predict its hysteretic behaviour and provide an efficient methodology for analyzing its seismic response . The results demonstrated that the pier exhibited exceptional seismic performance and deformability . Damage to the PRCFST pier was concentrated at the interface between the pier column and foundation slab, indicating that the connection form not only prevents significant damage to the foundation slab but also delays or mitigates local buckling of the steel tube. An increase in the axial compression ratio significantly reduced the ductility coefficient of the pier, while an increase in the width-to-thickness ratio significantly enhanced the ductility coefficient. A comparative analysis of test results and numerical simulations indicated that the developed restoring force model accurately predicted the hysteretic behaviour of the PRCFST pier. And the restoring force model provides valuable theoretical support for conducting elastic-plastic time-history analysis of such piers under seismic loading . • A prefabricated square reinforced concrete-filled steel tubular (PRCFST) pier with a grouting sleeve connection system is developed. • This PRCFST pier demonstrates outstanding seismic performance under low cyclic loading. • A restoring force model is proposed to accurately predict the hysteretic behaviour of the PRCFST pier.