Seismic retrofit of existing structures with rocking walls

The high occupancy levels in urban multi-story buildings, along with evolving safety standards, necessitate a reassessment of seismic performance objectives for structures.This study aims to explore a retrofitting and rehabilitation approach designed to enhance the resilience of existing buildings, with a broader objective of improving their performance under different conditions and prolonging their lifespan.In light of significant structural damage and documented weak-story failures observed after major earthquakes, this research examines the use of stepping rocking shear walls as a retrofit solution for moment-resisting frames (MRFs).This study begins with an overview of the current literature on rocking wall systems.Nonlinear time-history analyses are then conducted on two structural configurations-a 9-story and a 20-story MRFs-both in their original form and after retrofitting with stepping rocking shear walls.The results reveal that incorporating a rocking shear wall enhances first-mode dominance, leading to a more uniform distribution of interstory drift and significantly reducing the risk of weak-story failure.Additionally, the findings demonstrate that rocking shear walls effectively minimize residual drift, thereby improving post-earthquake operability while preserving structural integrity.Comparisons with FEMA P-58 performance criteria further highlight a decrease in damage probability and repair costs associated with the proposed retrofit method.Overall, the study underscores the potential of rocking shear walls as a viable and efficient retrofit strategy for enhancing the seismic resilience of both existing and new structures.