Experimental Assessment of Postearthquake Reusability and Repairability of Controlled Rocking Masonry Walls with Replaceable Energy Dissipation Devices

Abstract

Abstract Recent research on controlled rocking masonry walls has focused on self-centering mechanisms with accessible energy dissipation devices and enhanced toe protection strategies to improve seismic performance. Unlike post-tensioned rocking systems, where unbonded post-tensioning provides both the restoring force governing rocking initiation and additional stiffness through tendon elongation during rocking, energy dissipation–controlled rocking masonry walls (ED-CRMWs) and controlled rocking masonry walls with energy dissipation accessible in a steel base (EASt-CRMWs) rely on gravity load to provide the restoring force. While previous research studies on ED-CRMWs (flexural arms pinned to steel blocks embedded in the masonry wall) and EASt-CRMWs (flexural arms pinned to steel base) have advanced the understanding of their structural performance and energy dissipation mechanisms under seismic events, there has been limited focus on how the detailing of their bases affects their postearthquake behavior and capacity to support functional recovery. This paper presents the quasi-static experimental results from a two-phase program investigating the postearthquake performance of four ED-CRMWs and two EASt-CRMWs. Phase I evaluated reusability by subjecting walls to quasi-static cyclic testing after dynamic testing, simulating multiple seismic events without repairs. Phase II assessed repairability, where walls were repaired by replacing yielded flexural arms and damaged toes before further testing. One wall had no toe protection, while all other five walls incorporated various toe protection strategies, including steel plates, boundary elements, rubber pads, and steel bases. While the wall with no toe protection exhibited cracking and spalling in both phases, walls with toe protection through boundary elements, rubber pads, or steel bases showed significantly less damage, resulting in stable hysteretic behavior and reduced strength degradation. The residual drifts of all walls remained below the threshold for a minor damage state (DS1) even after testing to 5% drift, except the unconfined wall and the wall with rubber pads, which remained below DS2 and DS3 thresholds, respectively. The performance in Phase I showed reductions in initial stiffness and strength due to localized damage and yielded flexural arms, while the performance after repairs (Phase II) demonstrated full restoration of stiffness, postyield behavior and ultimate strength. The study highlights that ED-CRMWs and EASt-CRMWs can support rapid postearthquake functional recovery, advancing the seismic resilience of buildings by minimizing downtime and ensuring continued operation.