PERFORMANCE AND SEISMIC VULNERABILITY OF A TYPICAL CONFINED MASONRY HOUSE IN CUENCA-ECUADOR

The extent of damage in a city, in case of strong earthquakes, can be estimated from the results of the seismic
vulnerability of its most common construction type. The aim of the present contribution is to determine the seismic
vulnerability of a confined masonry building typical of Cuenca, Ecuador. Firstly, the macroscopic properties of
masonry are derived from mesoscopic finite analyses of masonry piers. Secondly, the proposed structure is modeled
using an equivalent frame method, in which masonry walls are defined as piers or spandrels using a macroelement
model. Thirdly, a pushover analysis is performed on the structure; the results of this analysis are used to define an
equivalent SDOF system. The properties of the SDOF are used to calibrate a single-macroelement model that
characterizes the cyclic behavior of the MDOF model. Both models are capable to reproduce in-plane shear and
flexural failure modes. Finally, nonlinear dynamic analyses are performed on the single-macroelement system for
different ground motions, which are obtained from natural records (SIMBAD data base) compatible with the
Ecuadorian design spectrum for several PGA levels. The maximum displacement of each analysis is compared with
defined limit states, the exceedance of a limit state is recorded and then fitted to a fragility function using the
maximum likelihood procedure. The proposed methodology presents an option for seismic vulnerability, to use in
scenarios where little data is available