Optimal seismic retrofitting of reinforced concrete buildings by steel-jacketing using a genetic algorithm-based framework

• Published in: Engineering structures Vol. 219; p. 110864
• Main Authors: Di Trapani, Fabio, Malavisi, Marzia, Marano, Giuseppe Carlo, Sberna, Antonio Pio, Greco, Rita
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 15.09.2020; Elsevier BV
• Subjects: Algorithms; Columns (structural); Concrete; Concrete construction; Deformation effects; Downtime; Earthquake loads; Frame structures; Genetic algorithm; Genetic algorithms; Optimization; Pushover; Reinforced concrete; Reinforcement; Reinforcing steels; Retrofitting; Seismic analysis; Seismic engineering; Seismic response; Steel; Steel jacketing; Three dimensional models; Pushover; Genetic algorithm; Steel jacketing; Optimization; Retrofitting
• ISSN: 0141-0296; 1873-7323
• DOI: 10.1016/j.engstruct.2020.110864

•An new framework for the optimization of steel jacketing retrofitting interventions on RC columns is presented.•The method can provide topological optimization (location) and amount of steel-jacketing reinforcement.•The optimization process is based on a genetic algorithm handling a fiber-section model realized in OpenSees.•The feasibility individual solutions is controlled by the capacity/demand ratio resulting from pushover analysis.•The application of the method can effectively reduce retrofitting costs maintaining a specified safety level.•The framework can be used by practitioners as a tool for sustainable retrofitting interventions. Retrofitting of existing reinforced concrete (RC) frame structures by steel angles and battens (steel-jacketing) is a commonly employed technique used to retrofit beams and columns against gravity and seismic loads. Steel-jacketing (SJ) effectively provides additional deformation and strength capacity to RC members but its application is associated with noticeable downtime of the building and non-negligible costs, depending on the amount of structural and non-structural manufacturing and materials. This paper presents an optimization framework aimed at the minimization of seismic retrofitting-related costs by an optimal placement (topological optimization) and amount of steel-jacketing reinforcement. In the proposed framework a 3D RC frame fiber-section model implemented in OpenSees is handled by a genetic algorithm routine that iterates reinforcement configurations to match the optimal solution. The feasibility of each solution is controlled by the outcomes of a static pushover analysis in the framework of N2 method. Results will provide optimized location and amount of steel-jacketing reinforcement, showing how effective and sustainable reduction of retrofitting costs is achievable maintaining a specified safety level.