Experimental Investigation of the Unreinforced Small Masonry Walls under Bidirectional Seismic Loading

During an earthquake, a wall is subjected to a three-dimensional acceleration field and undergoes simultaneous in-plane and out-of-plane loading. It is often noted that in the field of brittle material strength, presence of one type of loading on a structural element affects the strength of that element against another type of loading. Considerable number of numerical and experimental studies, carried out to-date to investigate the behaviour of masonry walls under seismic loading, have either considered the in-plane response or the out-of-plane response of the wall separately without due consideration for any possible interaction between the two responses. In this paper, the results of a series of tests with different levels of simultaneous in-plane shear and out-of-plane bending actions on small brick walls constructed with standard high strength mortar are presented. The tests results indicate noticeable interaction between the in-plane shear and out-of-plane bending strengths of brick walls. The interaction curve appears to follow a circular trend.