Lateral Strength-Based Seismic Evaluation of an Unreinforced Masonry Building

Abstract

Unreinforced concrete masonry (URM) buildings located in seismic areas still constitute an important portion of the residential building stock of Turkey. A significant amount of these buildings is designed according to allowable stress criteria of the 2007 version of Turkish Earthquake Code. However, seismic design philosophy, as well as seismic performance assessment, of URM buildings tends to focus on the lateral strength of URM walls and it is also adopted to the current version of Turkish Earthquake Code. Accordingly, the seismic performance of a URM building designed based on the theory of allowable stress is a significant concern. In this study, the seismic performance of a two-story URM building is investigated based on the ultimate strength method. The case study building is primarily designed in accordance with seismic requirements of the 2007 version of Turkish Earthquake Code. Subsequently, lateral strength-based seismic performance assessment of the same building is performed. The earthquake demand is represented by a 5%-damped elastic acceleration design spectrum and the lateral strengths of URM walls are calculated in accordance with provisions of the current Turkish Earthquake Code. All analyses are conducted on a very detailed three-dimensional finite element model (FEM) of the building. The results have shown that the lateral strength capacities of some URM walls located on the ground floor are exceeded, whereas none of the URM walls on the upper floor reach their capacities. As a result, collapse prevention performance level is not achieved.