Estudio del desempeño sísmico de estructuras sísmicamente aisladas mediante modelación 2D no lineal, considerando reducción de resistencia en su diseño estructural.

Abstract

In the following research, the seismic performance of a structure with a fixed base and with an isolation system is studied by modifying the strength reduction factors, as this influences the formation of plastic hinges and damage. The study focuses on a representative frame from a real project classified as essential, located in Portoviejo, Manabí, Ecuador. The modeling will be carried out using the open-source software OpenSeesPy, performing pushover and time-history analyses following the direct integration method. The project will be developed using 2D modeling with linear and nonlinear analyses applied to both the superstructure and the isolation system. The analysis will yield key results, including maximum displacement, ductility ratio, and performance, using different seismic records from the 2016 Pedernales earthquake. Based on the analysis results after modifying the strength reduction factors, the advantages of using isolation are confirmed, as a reduction in the analyzed parameters is observed compared to the fixed-base system. However, ductility demands significantly increase in isolated structures when strength reduction factors are raised. This highlights the importance of maintaining structures with isolators within elastic ranges to ensure their performance. The use of base isolation in buildings improves seismic behavior, but its effectiveness depends on the proper design of the primary system, ensuring it remains rigid under design-level earthquakes to avoid damage that could compromise its performance. Keywords: seismic isolation, OpenSeesPy, strength reduction, nonlinear modeling.