In-plane drift capacities of non-ductile and limited ductile rectangular reinforced concrete shear Walls: empirical predictions

Abstract Reinforced concrete (RC) walls with single-layer (non-ductile walls) and double-layer (limited-ductile walls) reinforcement are commonly used in buildings located in low to moderate seismic regions. Despite being designed for adequate in-plane strength, the drift capacities of these walls remain a concern due to the absence of end confinement detailing. It has been recognised that a better understanding and more accurate estimation of wall drift capacities, using available empirical evidence, is essential for assessing and reducing the risk of structural instabilities observed in past earthquakes. To this end, an experimental database comprising 47 single-layered and 49 double-layered RC walls was developed, capturing the results of past in-plane cyclic shear tests. The database provided insights into the failure patterns and geometrical and mechanical parameters influencing the drift capacities of these walls. The analyses revealed that the double-layered RC walls generally possess higher drift capacities than their single-layered counterparts. The drift capacities of these walls were found to be influenced by complex parameters, including the effective slenderness ratio $$\left( {{\lambda _t}} \right)$$ , shear stress demand $$\left( {{V_u}/{A_g}\sqrt {{f_c}} } \right)$$ , and axial load ratio $$\left( {P/{A_g}{f_c}} \right)$$ . The existing empirical models, which were primarily developed for RC walls with special detailing in high-seismic regions, systematically over-predict the drift capacities of the non-ductile and limited-ductile walls considered in this study. Consequently, a new set of empirical formulations was developed to predict the drift capacities of single-layered and double-layered rectangular RC walls with non-ductile or limited-ductile detailing, as commonly used in regions of low to moderate seismic hazard. The proposed models were calibrated using regression analyses, demonstrating strong alignment with experimental results.