This paper summarizes a study whose primary objectives were to develop a model for nonlinear static analysis of unreinforced masonry (URM) buildings, considering the flexibility of the floor system and analyzing the influence of stiffening the floor system on the overall seismic response of such buildings. With this aim, a six-story building typical of the Eixample-Barcelona district was used as a case study. All the macro-elements, those that constitute the walls and the floor system, were developed with one-dimensional spring elements. The influence of stiffening the floor system was analyzed by applying conventional stiffening interventions to the two floor systems common in the Eixample-Barcelona district.
2The overall seismic response was evaluated in terms of modal parameters, the characteristics of the pushover curves and the deformed shape of the floors. The outcomes are discussed in relation to recent studies and explained in the context of previous studies. Finally, in the two unstiffened cases of the prototype building, the stiffening of the floor system slightly increases in fundamental periods, slightly to moderately increases in base shear capacities, and significantly decreases in displacement capacities.
The Historic Center of Cuenca (HCC) is located in the southern region of Ecuador. It is well known that our country is located on the so-called belt of fire of the Pacific Ocean, this area is characterized by having generated the most important seismic events in the history of mankind. More specifically, there are records that show that in the last 200 years the city of Cuenca has been exposed to earthquakes that have produced moderate to severe damage. These reasons make it possible to establish that the city of Cuenca and specifically its historic center could present important problems in the face of significant seismic events. Most of the buildings in the HCC date back to the middle of the 20th century and have used unreinforced brick masonry (brick-URM) to build their walls. This work is part of the Seismic Vulnerability Project: Seismic Damage Scenarios of the Built Heritage of the Historic Center of Cuenca. In the context of this vulnerability project, the objective of this work was to establish a family of pushover curves for three unreinforced brick masonry buildings typical of the HCC, based on a parametric pushover analysis. The definition of the typical buildings was based on an extensive work of architectural and geometric characterization of the traditional built heritage of HCC. On the basis of focusing the study on two-story buildings (the most common), the size of the floor area of the buildings (small, medium and large area) was assumed as a base parameter. Based on an analysis of the variability of different geometric and mechanical characteristics, and in order to study their influence on the pushover curves of the three typical brick URM buildings, the following study parameters were defined: 1) compressive strength of brick masonry, 2) lateral displacement capacity of brick-URM elements, 3) wall thickness. The pushover analysis was carried out with the Ruaumoko program. The model of the buildings responds to an equivalent portal frame macro-model scheme that has been formulated and validated by the authors of this paper. In order to consider the effects of the flexible floor on the dynamic response of this type of structures, a lateral load pattern that takes into account the contribution of higher order modes of vibration will be used in pushover analysis. The results will be discussed in terms of the incidence of the variability of the study parameters on the basic characteristics of the pushover curves. These results will be an essential input for the next stage of the project consisting of damage estimation for different levels of seismic action expected in the city.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.