Evaluación sísmica del edificio patrimonial del antiguo Colegio Borja utilizando macro modelización dentro del esquema pórtico equivalente

Abstract

The thesis addresses the seismic response of the Antiguo Colegio Borja (ACB), a heritage building made of unreinforced masonry in Cuenca, Ecuador. Built with bricks and lime mortar, it has flexible floors and walls with openings that affect its rigidity. It was modeled using macromodeling with 3Muri software, using the Equivalent Frame Approach (FME/FEA) that allows its analysis through its geometric and mechanical properties. A detailed survey was carried out that included wall thicknesses, opening dimensions, and floor characteristics to evaluate its behavior as rigid diaphragms. According to the results, the modal analysis identified 66 vibration modes, with a mass participation factor greater than 90% in both directions, complying with regulations. The first mode, with a period of 0.32 s, indicates a relatively rigid structure. Pushover analyses with uniform and triangular loads showed non-linear behavior, with sequential failure mechanisms and redistribution of forces. Fractures due to bending, compression, and shearing were detected in specific elements, in addition to the ineffectiveness of certain structural components. To improve seismic response, three strategies are proposed: increasing wall continuity by reducing spans to improve stiffness and strength; dividing the building into independent blocks using structural joints to mitigate irregularities in the floor plan; and stiffening floors and roofs with a reinforced concrete slab that ensures adequate rigid diaphragm behavior, preventing out-of-plane failures. These measures seek to preserve the historical value of the ACB and ensure its safety in the event of seismic events.