Seismic resilience of retrofitted RC buildings

Existing buildings can be at a greater seismic risk due to non-conformance to current design codes and may require structural retrofitting to improve building performance.The performance of buildings is measured in terms of immediate consequences due to direct damage,but the continuing impacts related to recovery are not considered in seismic retrofit assessment.This paper introduces a framework of retrofit selection based on the seismic resilience of deficient buildings retrofitted with the conventional mitigation approaches.The assembly-based methodology is considered for the seismic resilience assessment by compiling a nonlinear numerical model and a building performance model.The collapse fragility is developed from the capacity curve,and the resulting social,economic,and environmental consequences are determined.The seismic resilience of a building is assessed by developing a downtime assessment methodology incorporating sequence of repairs,impeding factors,and utility availability.Five functionality states are developed for the building functionality given investigated time interval,and a functionality curve for each retrofit is determined.It is concluded that seismic resilience can be used as a performance indicator to assess the continuing impacts of a hazard for the retrofit selection.

Long-term sustainability and resilience enhancement of building portfolios

The role of community building portfolios in socioeconomic development and the growth of the built environ-ment cannot be overstated.Damage to these structures can have far-reaching consequences on socioeconomic and environmental aspects,requiring a long-term perspective for recovery.As communities aim to enhance their resilience and sustainability,there is a cost burden that needs to be considered.To address this issue,this pa-per proposes a community-level performance enhancement approach that focuses on optimizing the long-term resilience and sustainability of community building portfolios,taking into account recurrent seismic hazards.A Gaussian process surrogate-based multi-objective optimization framework is utilized to optimize the cost objec-tive while considering performance indicators for resilience and sustainability.The proposed framework involves using performance-based assessment methods to evaluate the socioeconomic and environmental consequences under stochastic and recurrent seismic hazard scenarios.These evaluated indicators are then used to efficiently optimize the community resilience and sustainability,taking into account the retrofit costs.Finally,approximate Pareto-optimal solutions are extracted and utilized for decision-making.In summary,this paper presents a novel approach for optimizing the long-term resilience and sustainability of community building portfolios by consid-ering recurrent seismic hazards.The proposed framework incorporates performance-based assessment methods and multi-objective optimization techniques to achieve an optimal balance between cost,resilience,and sustain-ability,with the ultimate goal of enhancing community well-being and decision-making in the face of seismic hazards.