Behavior and analysis of masonry-infilled reinforced concrete frames subjected to lateral load

Infilled frame constructions have been in use for more than 200 years. Masonry infills have often been treated as nonstructural elements and their structural presence is often ignored by engineers. The infill panels may interact with bounding frames when the structure is subjected to strong lateral loads induced by seismic load. Such interaction shows some positive and negative effects on the structure and has been the subject of many debates. The experimental results demonstrated that the masonry infill walls benefit the buildings due to the amount of increase in the initial stiffness of the reinforced concrete frames. On the other hand, infill walls have been related to failures, such as the development of soft stories and the brittle shear failure of columns induced by the short-column effect. In spite of the structural effects of bounding frames, masonry infills have not been treated in EC 8. During the last 50 years, a number of different analytical models (micro- and macro-models) have been developed to evaluate infilled structures under in-plane and out-of-plane horizontal dynamic actions. This paper presents a literature review of analytical research conducted on infilled frames, compares design provisions related to masonry infill in seismic design codes of different countries and discusses the shortcomings of the national guidelines.