Theoretical method for predicting the failure mode of reinforced concrete shear walls subjected to axial tension and cyclic lateral loads

Abstract

Reinforced concrete shear walls may exhibit various failure modes when subjected to combined axial tension-flexure-shear loads. This study developed a theoretical method for predicting the failure mode of RC walls subjected to combined axial tension and cyclic lateral loads, in which the force-displacement response curve was compared to the predicted flexural, shear and sliding strength capacity curves. The formulas for calculating the axial elongation and horizontal crack widths of tensile RC walls were proposed, and the influence of these two aspects was fully considered in the estimation of shear strength and sliding strength degradation. The proposed method was validated against test data of ten RC wall specimens which underwent various failure modes, including flexural, shear, sliding, flexural-sliding, and shear-sliding failure modes. Comparisons between experimental and theoretical results indicated that the proposed method predicted the failure modes and lateral strength with acceptable accuracy. As the proposed method accurately estimated the shear and sliding strength degradation, it provided the insights on the shifting of dominated behaviors (e.g., flexural- or shear-dominated behavior to sliding-dominated behavior). Finally, strength design formulas specified in Chinese, US and European codes were verified against test data. The flexural strength of RC walls was reasonably estimated by the JGJ 3–2010 (Chinese code), ACI 318–19 (US code) and Eurocode 8 (European code) design formulas. Among the three codes, JGJ 3–2010 provided a more reasonable estimate on shear strength of tensile RC walls than the other two codes.