Comparing the performance of traditional shear-wall and rocking shear-wall structures designed using the direct-displacement based design approach

Abstract

Reinforced concrete shear walls are widely used as lateral load resisting systems because of their favorable characteristics that include high strength, stiffness, ductility and energy dissipation. In most instances, these systems rely on the activation of a flexural mechanism at their base, where substantial damage is expected. Base-rocking systems have been proposed as a way to address this issue, mitigating severe structural damage while still limiting the seismic demands experienced by the structure. However, even when the base moment is limited, structural forces, moments and accelerations along the height of the structure can increase significantly because of higher mode effects. While this holds true for both traditional and rocking shear wall structures, past studies have suggested that rocking systems may be more prone to attract higher seismic demands. This article evaluates the performance of a set rocking shear wall structures against that of traditional reinforced concrete wall systems. The case study structures are analyzed via non-linear time history analyses, under a suite of spectrum compatible ground motions. The results of the numerical analyses confirm that while the overall performance of the rocking systems is superior to that of the “equivalent” traditional wall structures, they tend to be subjected to somewhat higher peak seismic demands.