Seismic Reliability of Masonry-Infilled RC Frames

Abstract

This study focuses on the probabilistic assessment of reinforced concrete (RC) frames infilled with clay brick walls and subjected to earthquake loading. The adopted methodology extends that previously developed by the writers for bare RC frames by introducing additional random variables to account for the uncertainty in the masonry properties. Quantification of the latter is achieved through the use of experimental data describing the difference in force-displacement behavior between bare and infilled frames. The vulnerability and seismic reliability of two 10-story, three-bay infilled frames (a fully infilled one and one with a soft ground story) are derived and subsequently compared with values corresponding to the bare frame counterpart. It is found that failure probabilities, especially at the ultimate limit state, are highly sensitive to the structural stiffness; hence, bare frames benefit from lower spectral ordinates than infilled ones. Nonetheless, all structural systems studied appear to be exposed to a reasonably low seismic risk.