Evaluación de vulnerabilidad sísmica de edificaciones de estructuras metálicas en la parroquia La Matriz, Ambato, Ecuador: Propuesta de reforzamiento estructural de una edificación representativa

Abstract

The city of Ambato is one of the areas with high seismic hazard in Ecuador, this parameter combined with the vulnerability of the buildings and the level of exposure represent the level of seismic risk that could occur in the event of seismic events. The vulnerability of buildings is the only variable that can be influenced to reduce the level of risk, since it depends on aspects such as the type of structural system, presence of irregularities in plan and elevation, level of maintenance of the building, application of regulations and building codes, and other parameters that are controllable. For this reason, it was essential to evaluate the seismic vulnerability of existing metal structure buildings to provide an overview of the degree of vulnerability of buildings in La Matriz district and, related to this, the seismic risk index. To evaluate the seismic vulnerability, methodologies approved by national and international entities were used, such as the NEC 15, FEMA P-154 and FUNVISIS rapid visual inspection forms, which showed good results to evaluate a wide range of buildings and collect general data for the La Matriz district. Based on this analysis, the Plaza Cívica Mercado Urbina was selected for a more detailed vulnerability analysis using computational resources to apply linear static, spectral modal, and nonlinear static analysis. With the detailed methodology it was possible to know in detail the conditions in which the building was found and the seismic performance, it was determined that the structural system is robust and that it behaves rigidly in the presence of seismic loads, however, there are construction details that could generate collapses by rupture failure mechanisms in the areas of stress accumulation, this was the case of the connections between beams and columns. To mitigate future problems in the building, a system of reinforcement and stress dissipation was proposed by means of a finite element analysis. Finally, suggestions were made to maintain the structural system in favorable conditions for service conditions.