Generalized Shear Strength Model for Wall/Slab L-Joints in Steel-Plate Composite/Reinforced Concrete Structures

In safety-related nuclear facilities, steel-plate composite (SC) structures are typically integrated with reinforced concrete (RC) structures, forming five types of L-joints, including SC wall–SC wall, SC wall–RC wall, SC wall–RC slab, RC wall–RC wall, and RC wall–RC slab joints. Despite recent experimental studies consistently indicating the high susceptibility of such joints to shear failure, the sensitive parameters influencing joint shear strength are not clear, and the prediction results of the available empirical model are not reliable. This paper contributes to addressing this gap and proposes a generalized shear strength model for the aforementioned five types of SC/RC L-joints. First, this study found that the reinforcement ratios of longitudinal rebars, steel plates, and transverse rebars, as well as the shear span-to-depth ratio, are sensitive parameters that significantly influence the shear strength of the joints, despite being overlooked in the existing strength model. Then, a modified Mohr-Coulomb failure criterion suitable for SC/RC L-joints considering the preceding sensitive parameters was developed, followed by the proposal of an analytical model for joint shear strength. Subsequently, to further quantitatively evaluate the influence of unsolvable variables in analytical model, a detailed 3D finite element model was developed and conducted the parametric study. Finally, based on this a semianalytical model was developed. Validation results indicate that the model exhibits significantly higher predictive accuracy compared to the existing model.