Repairability and Damage Assessment of Controlled Rocking Masonry Walls with Energy Dissipation Accessible in a Steel Base

Abstract

ABSTRACT In recent years various studies have explored the seismic behavior of controlled rocking masonry walls (CRMWs) that utilize both gravity loading for self-centering and additional energy dissipation (ED) devices to regulate the response (ED-CRMWs). However, these studies had limitations because ED devices were installed on or within the masonry wall, making repairs difficult or impossible after ED yielding or fracturing. This study presents the testing of two half-scale CRMWs that were constructed with supplemental flexural yielding Energy dissipation devices Accessible in a Steel base (EASt-CRMWs). The proposed EASt-CRMWs simplify the installation of the energy dissipation devices and overall wall construction, while also allowing for easy replacement following damage. The walls were subjected to quasi-static, cyclic loading up to drifts of 2.35%, after which the ED devices were replaced, and the same wall was tested again. Wall 2 was built with a steel plate at the rocking point between the steel base and the foundation interface. All five tests demonstrated a favorable self-centering response, with no significant damage to the walls. The ED devices were easily replaced between tests, and the damage was confined to them. Wall 2 had better performance because of the steel plates, which reduced damage to the mortar at the steel base-foundation interface, resulting in slightly decreased lateral load capacity at lower drift ratios upon retesting for Wall 1. Moreover, residual drifts were below 0.05% for all wall tests. Finally, a numerical model and a damage index proposed previously were validated based on the experimental work presented in this study as well as additional configurations of EASt-CRMWs presented in a previous recent study. The results demonstrate that the model can capture the overall response of the walls, and the damage index can accurately predict the location, type, and severity of the damage.