型钢混凝土短梁面外刚度和承载性能研究

To meet the demands of modern architectural spatial design, a special structural configuration has emerged in engineering practice where columns are positioned outside the beam-column joints and connected solely to horizontal beams, forming unidirectional leap-story columns. The out-of-plane stability of such columns is governed by the out-of-plane mechanical performance of short horizontal beams at the joint periphery. This study investigates the out-of-plane shear behavior of steel-reinforced concrete (SRC) short beams acting as joint-side horizontal beams, aiming to clarify their restraining effects on the out-of-plane stability of leap-story columns. Six SRC short beam specimens were designed and subjected to out-of-plane shear tests under mid-span concentrated loading, systematically examining the influence of shear span-to-depth ratio (λ is 1. 0-2. 5) on failure modes, stiffness degradation, shear capacity, and deformation characteristics. Results indicate that specimens exhibit diagonal compression failure at λ≤1. 5 and transition to shear-compression failure at λ = 2. 5. As λ increases from 1. 0 to 2. 5, the initial stiffness decreases by 92%, shear capacity declines by 60%, while displacement ductility coefficient improves by 23%. Theoretical equations for out-of-plane stiffness and shear capacity of SRC short beams were established based on the superposition principle and existing codes, with deviations between calculated and experimental values below 10%, confirming the reliability of the proposed models.