Evaluación del desempeño sísmico en edificios irregulares de mediana altura de hormigón armado, mediante análisis no lineal dinámico, bajo registros sísmicos de Ecuador

Abstract

This graduation project evaluates the seismic performance of mid-rise reinforced concrete buildings with structural irregularities in plan and elevation using nonlinear time-history analysis based on real seismic records from Ecuador. The objective is to assess the influence of structural irregularity on inelastic response, displacement demands, and damage concentration, under the hypothesis that irregular configurations exhibit seismic performance governed by more critical damage mechanisms when compared to regular buildings. The study is motivated by the high seismic hazard of the country and the need to better understand the inelastic behavior of structural configurations commonly encountered in local practice. The project was developed through three-dimensional numerical modeling of reinforced concrete benchmark buildings with regular and irregular configurations, incorporating material nonlinearity by means of fiber-based plastic hinges. Real seismic records from the 2016 Pedernales earthquake were selected and processed, and subsequently applied as input motions in nonlinear dynamic analyses. The results showed increases in maximum interstory drifts, lateral displacements, and damage concentration in the irregular models, with differentiated structural responses. Plan irregularity led to higher demand concentration at intermediate stories, whereas vertical irregularity triggered soft-story mechanisms at the base. Based on the evaluation, it is concluded that buildings with structural irregularities may exhibit global displacement demands comparable to those of regular configurations, while concentrating inelastic response and damage in specific regions of the structural system. Keywords: nonlinear time-history analysis, seismic performance, irregular buildings, benchmark models, reinforced concrete.