Structural models for calculating shear force in columns due to masonry-frame interaction in concrete building under seismic loads

Abstract

In seismic analysis, it is crucial to consider the interaction between the infill walls and the concrete frame in order to prevent local failures in RC columns. To this end, this paper presents a comparative study of the different structural models to determine the additional shear force in reinforced concrete columns due to the interaction between masonry and structure under seismic loading, for design applications. Simplified models using a single equivalent diagonal strut and multiple equivalent diagonal struts for the simulation of masonry infill structures were investigated. The efficiency of such models was evaluated based on two- and three-dimensional modelling using the Finite Element Method by simulating the contact problem between the masonry infill and the concrete frame. These comparisons focus on examples of single and multi-story masonry infilled frames. The results obtained confirm that the classic concentric strut model significantly underestimates the values of the maximum shear forces in the columns and that these values can be better predicted if the model is adapted for the transfer of the axial force of the equivalent diagonal strut along the contact length of the column and wall.