Experimental and Analytical Lateral Performance of Shear Walls with Variable Phases of Deformation

Abstract

Conventional reinforced concrete shear walls are widely used as primary lateral-force-resisting members owing to their high in-plane stiffness. However, some of these walls have been severely damaged in past earthquakes because of their limited energy dissipation capacity and ductility, thus requiring laborious repairs or even demolition. Self-centering rocking walls have recently been developed and proven effective for reducing the damage and residual displacement of structures after earthquakes. Because self-centering rocking walls are usually constructed by releasing constraints at the foundation, their contribution to structural stiffness may be limited, and they are very vulnerable to vibration. To overcome these limitations, a shear wall with variable phases of deformation was proposed; this wall consists of a rocking bearing, low-strength concrete zones, and buckling-restrained rebars. With increasing seismic intensity, the proposed wall first exhibits the shear–bending deformation mode of conventional reinforced concrete shear walls, which transitions into the rocking deformation mode of self-centering rocking walls. Cyclic loading tests were conducted to investigate the seismic performance of the proposed wall. The results demonstrated that the presented concept of the mechanism transformation is feasible in practice, and compared with conventional shear walls, the proposed wall displays improved seismic performance in terms of the damage mechanism, lateral resistance degradation, and deformation capacity. Moreover, a spring–truss model and a performance prediction model were also developed to predict the seismic performance of the proposed wall. Validating the predictions of the analytical models against the test results confirmed the accuracy of the developed models.