Seismic vulnerability analysis of a two-story family dwelling in confined masonry in Cuenca, Ecuador

Abstract

This paper presents a seismic vulnerability assessment of a single-family dwelling in confined masonry, a common construction type in the city of Cuenca, Ecuador. The macroscopic properties of hollow and solid brick masonry are derived from mesoscopic finite element analyses of masonry piers. The structure is modeled using an equivalent frame method, in which masonry walls are defined as piers or spandrels using a macro-element model; reinforced columns and beams and orthotropic floor slabs are also included. Several models, considering a deterministic geometry and stochastic properties of masonry, are analyzed using a quasi-static pushover method. The results of these analyses are used to define a single equivalent macro-element that incorporates in-plane shear and flexural failure modes and is capable of reproducing the cyclic behavior of the 3D model. Non-linear dynamic time history analyses are finally performed on the single equivalent macro-element for different earthquake ground motions that are selected from the PEER Ground Motion Database and that are compatible with the Ecuadorian design spectrum for several PGA levels. The maximum response is compared with different performance levels and the fragility curves are determined using a maximum likelihood analysis. The proposed methodology can be used for seismic vulnerability analysis when few data are available, but is subject to high levels of uncertainty, so further analysis and experiments on materials and structural components are needed.