Lateral resistances of RC shear walls controlled by shear and sliding failure modes under axial tension

This study delved into the shear and sliding performances of RC shear walls subjected to combined axial tension and lateral shear, which may occur at the bottom of high-rise buildings under strong earthquakes. An extensive database comprising 41 RC shear walls tested under tension-shear was established, and the tests were categorized based on their failure modes. The study evaluated existing shear and sliding resistance models based on the collected database and introduced novel models for both shear and sliding resistances. The coefficients of variation for ratios of tested-to-predicted capacities of the proposed shear and sliding models are 0.18 and 0.24, respectively, significantly lower than those of the existing shear models and sliding models. A parametric analysis was conducted on the proposed models and the code models, and finite element results were used for verification. The results indicated that the proposed models not only effectively captured the influence of shear spanto-depth ratio, concrete strength, reinforcement ratios, and axial tensile force on the shear and sliding capacities of RC shear walls, but also well reflected the transition of shear and sliding failure modes. Furthermore, a numerical analysis was conducted to explore the impact of flange width on the shear capacity of shear walls. The numerical results confirmed that the proposed shear model effectively reflects the enhanced shear capacity due to the presence of flanges. However, predictions by ACI 318-19 and JGJ 3-2010 noticeably underestimated this effect.