Seismic design and analysis of masonry-infilled frames

A simple analytical procedure, which can be used by practicing engineers, for the seismic design of masonry-infilled frames is presented. The analysis procedure, based on the experimental and analytical studies reported in the literature, accounts for the effect of infills in all three stages, namely, in computing seismic loading, in predicting response of the infilled frame, and in determining the strength of the infilled frame. Seismic loading is computed using the dynamic properties of the structure rather than arbitrary empirical relationships as recommended in design codes. Recommendations regarding the choice of infilled frame idealization, structural damping ratio, earthquake design spectrum, structural irregularity, and computational aids are made. Practical guidelines, which can be implemented during the construction phase and which have beneficial effects on the behaviour of infilled frames, are provided. Application of the proposed analytical procedure in a design situation is demonstrated through a numerical example, and it is shown that infills can be accounted for in the seismic design of frames during the normal course of design.