Experimental study on damage-controllable rocking walls with resilient corners

Abstract

Polyurethane elastomer was employed in the concrete rocking element in an innovative way to limit the corner damage during rocking. A damage-controllable rocking wall consisting of rocking elements, resilient corners, connecting beams, unbonded post-tensioned tendons and replaceable dampers was developed. Cyclic tests on damage-controllable rocking walls were conducted by changing the conditions of dampers, corner elastomers and tendons to investigate their seismic performance. Two sets of reusable reinforced concrete rocking elements were repeatedly used seven times. The horizontal displacement of the specimen was mainly caused by rigid body rotation. The deformations of the rocking elements were quite limited, and no flexural cracks were observed in any tests. All the specimens performed well with a good capacity for low damage. Energy dissipation was generated by the attached dampers, and the equivalent viscous damping coefficient of the proposed wall was proportional to the yield strength of dampers. The damaged damper can be replaced conveniently after each test, whereas the corner elastomers remained elastic. Specimens without damping exhibited a bilinear elastic response and were completely self-centring after testing. Specimens with a suitable initial post-tensioned force and damping exhibited flag-shaped hysteresis with minor residual drifts.