Study on seismic performance and restoring force model of flush-end square boundary-web all-bolted connected RC shear walls

To improve the construction efficiency and reliability of prefabricated shear wall structures, a flush-end enhanced all-bolted web-connected joint was proposed in this study. Five specimens with different connection configurations were designed and tested under cyclic lateral loading to investigate the failure mode, ultimate bearing capacity, ductility, stiffness degradation, and energy dissipation capacity of the proposed precast shear wall system. The test results indicated that, for the weak-connection specimens, buckling occurred in the web and cover plates of the steel connection region, while the concrete portion remained generally intact. In contrast, for the strong-connection specimens, diagonal cracking developed in the reinforced concrete wall panel, whereas the steel connection region remained basically undamaged. Compared with the cast-in-place specimen, the proposed precast wall exhibited an increase of approximately 8.04% in yield load, 7.36% in initial stiffness, and 50% in yield-stage energy dissipation capacity, demonstrating excellent lateral resistance performance. Strain analysis revealed that, with the further increase in steel plate thickness, the steel connection region produced a significant confinement effect on the wall panel. The sectional stiffness ratio between the reinforced concrete region and the steel connection region was recommended to be within the range of 2.0–2.4. Based on the experimental results and the trilinear idealization method, calculation methods for the bearing capacity and initial stiffness of the proposed shear wall were developed, and a corresponding restoring force model was established. The present study can provide a theoretical basis for the engineering application of this novel precast shear wall system.