Seismic performance of reinforcement-lapped square CFST column base

• A novel column base with lapped reinforcements was proposed for square CFST column. • A cyclic loading test was conducted on the column base specimens to investigate key parameters of reinforcement ratio, lap length of lapped reinforcements, and configuration of PBL. • A finite element (FE) model for the column base was developed and parametric study was performed. • A calculation method for determining the combined compression-bending capacity along with reasonable constructional measures was proposed. This study proposes a square concrete-filled steel tubular (CFST) column base with lapped longitudinal reinforcements, and focuses on the investigation of its seismic performance experimentally and analytically. A quasi-static test on five reinforcement-lapped square CFST column bases is first conducted to evaluate the seismic performance, considering the key parameters of reinforcement ratio, lap length of lapped reinforcements, and configuration of the perfobond rib (PBL). The test results of failure modes, bearing capacity, ductility, energy dissipation capacity, and stress distribution, indicating that the proposed column base exhibits good seismic performance. The bearing capacity, ductility, and energy dissipation capacity are comparable to traditional embedded CFST column bases. To further investigate the force transfer path and stress distribution characteristics of the column bases, the software ABAQUS is used to establish a finite element model . Additionally, a calculation method for determining the combined compression-bending capacity is proposed. Validated against the experimental results, the proposed calculation method accurately predicts the bearing capacity of reinforcement-lapped square CFST column bases, making it suitable for practical applications.