Enhancing Structural Resilience through seismic retrofitting through externally attached sub structures

Abstract

This study pays attention to improving structural resilience to seismic occurrences by seismic retrofitting with externally attached substructures. A comparison of several bracing systems, including X, Chevron, V, Global, and mixed forward and backward bracings, was performed and modelling was carried out on ETABS software 2020 version. We also used Seism match software for spectral matching of real time earthquake data with our designed spectrum. Different earthquakes Imperial, Kobe, Kern, Northridge with RSN numbers 184, 1106, 12, 1044 and 1063 respectively were applied during the simulation. The study found that Chevron, X, and Global bracings are the most effective at mitigating seismic responses such as story displacement, story shear, base shear, and joint story displacement relatively. The efficiency of the chosen bracing systems was further evaluated through plastic hinge analysis under simulated seismic circumstances utilizing historical earthquake data (Kobe, Imperial, Kern, Northridge) and matching Record sequence number (RSN) values. The results demonstrated that the application of these bracings significantly enhances the structural capacity of nonseismic code based designed buildings to prevent collapse and performing to fullest in non-linearity stage, achieving the “Collapse Prevention” performance level and reaching the “Immediate Occupancy” threshold as per hinge safety criteria. Furthermore, the thesis investigated into the environmental sustainability of bracing systems, suggesting that by incorporating bracings/substructures, it contributes positively to sustainable practices and offers a proactive mindset to future seismic risk mitigation. This study underlines the importance of retrofitting strategies in the pursuit of safer and more resilient built environments and safer world.