Seismic performance of a topological interlocking precast segmental column based on concrete-filled double steel tube configuration

This study proposes a novel topological interlocking precast segmental column (TIPSC) based on a concrete-filled double steel tube (CFDST) configuration, aiming to address the limitations of conventional precast segmental columns (PSCs), including insufficient energy dissipation pathways and toe-dominated damage concentration. In the proposed system, the conventional sandwiched concrete core is replaced by a topological interlocking (TI) brick assembly, introducing distributed interfacial contact and frictional sliding as additional energy dissipation mechanisms. A detailed finite element model is developed based on a PSC benchmark experiment, and subsequently employed to compare the cyclic responses of TIPSC and PSC. Furthermore, parametric studies are conducted to investigate the effects of prestressing level, energy dissipation (ED) bar ratio, and TI configuration on the structural performance of TIPSC. Results show that, compared with the PSC benchmark, the TIPSC exhibits a fuller flag-shaped hysteresis, enhanced lateral strength, and increased activation of the frictional dissipation mechanism, while maintaining effective control of residual deformation. In addition, the TIPSC demonstrates delayed damage localisation and improved stiffness retention. Parametric analyses reveal that a moderate ED bar ratio combined with a higher prestressing level provides a balanced performance between self-centring capacity and energy dissipation, while an intermediate TI interlocking level is recommended to ensure effective frictional dissipation while maintaining sufficient kinematic compatibility. Specifically, through rational design of TI configuration and prestressing level, the demand for ED bars can be effectively reduced. These findings provide valuable design insights for the development of resilient segmental column systems.