Capacidad sísmica y umbrales de daño en edificaciones de mampostería no reforzadas típicas del Centro Histórico de Cuenca

Abstract

Ecuador is in the Pacific Ring of Fire. It is a zone with high tectonic activity. Therefore, its population and infrastructure must be prepared to face seismic environments. It is the case of Cuenca, a city recognized by UNESCO as an Intangible Cultural Heritage of Humanity in 1999 due to its historic architecture with masonry buildings dating back more than a century. Between the 1940s and 1980s, the use of unreinforced masonry-bearing walls combined with flexible floor systems became popular in the construction of buildings. However, the lack of confinement and reinforcement in this type of structure results in poor seismic behavior compared to modern construction techniques. It emphasizes the need to evaluate their seismic capacity. In the present work, MNR buildings are characterized as a function of time and size, considering geometrical aspects such as the distribution of openings, inter-story heights, walls, and joint thicknesses. In addition, the mechanical properties of brick, mortar, and masonry are analyzed and characterized. Nine models representing the different construction periods were studied using two-dimensional macro-elements. Also, a family of capacity curves using nonlinear static analysis is studied. Subsequently, limit states are analyzed, and damage thresholds are established according to the NTC2018 standard. The results are analyzed in terms of ductility and maximum base shear.