Experimental study and numerical modeling of coupled reinforced concrete walls

Abstract

Reinforced concrete shear walls are widely used as an effective solution for resisting lateral seismic loads across various building typologies. Particularly in Chile, these walls represent the predominant lateral load resisting system in high-rise buildings, with their use being more common in residential developments. The typical configuration for these buildings consists of a series of shear walls interconnected by cast-in-place reinforced concrete slabs at each story level. As a result, the structural behavior of the individual shear walls is modified by the coupling effect induced by the floor slabs. The primary objective of this study is to understand the structural behavior of reinforced concrete coupled walls subjected to axial loads and cyclic lateral displacements. In particular, the distribution of cross-sectional curvature along the height of each shear wall in the coupled system is examined. For this purpose, a cyclic pseudo-static experimental set of tests was conducted, where each specimen consisted of two individual scaled reinforced concrete walls, interconnected by beams on each story level. The specimens were designed to replicate coupled wall systems of 15 and 25 stories, using a scale factor of 1:35. OpenSees fiber models were developed and validated against the available experimental data, demonstrating close agreement between the numerical predictions and the test results. Building on this validation, a parametric study was carried out using the calibrated numerical model. The study explored a range of realistic wall parameters to examine the influence of coupling on the curvature demand of interconnected walls. The results revealed that when two individual shear walls of different lengths are interconnected, neglecting the coupling effect can lead to an underestimation of up to three times the curvature of the shorter wall. Conversely, the coupling effect was found to have a minimal impact on the curvature of the longer walls. Finally, a novel yet simplified analytical expression is proposed to estimate the ultimate curvature at the base of the shorter structural walls.