Many buildings damaged during earthquakes remain in service because immediate demolition is often impractical. Conventional seismic rehabilitation typically evaluates strengthening using intact models, neglecting residual deformation and stiffness degradation from prior earthquakes. This study proposes a damage-informed three-stage framework for seismic rehabilitation, in which rehabilitation measures are applied directly to the damaged structure and its performance is evaluated under subsequent seismic events. The effectiveness of the framework is demonstrated using five- and ten-story RC frames equipped with pure-bending dissipator devices as supplemental energy-dissipation devices. Nonlinear dynamic analyses and Endurance Time evaluations were performed under multiple mainshock–aftershock scenarios, and a probabilistic damage assessment was conducted using a lognormal fragility framework based on Hazus damage-state limits. Results show that the proposed strategy reduces peak inter-story drifts by up to 45% and prevents extensive damage under subsequent seismic events. Although the proposed framework predicts higher aftershock vulnerability than conventional rehabilitation approaches, this is attributed to the explicit consideration of pre-existing damage, thereby providing a more realistic estimate of structural performance. The proposed methodology provides a practical, computationally efficient basis for performance-based seismic rehabilitation by explicitly incorporating cumulative earthquake damage into both retrofit design and assessment.
