Peak and residual strengths of brick masonry spandrels

Unreinforced masonry (URM) walls comprise vertical piers and horizontal spandrels, which together form the lateral load resisting system. Whereas past research yielded significant advances in the understanding of the force-deformation characteristics of masonry piers, knowledge of the behaviour of masonry spandrels is lacking. This paper makes a contribution to our understanding of the seismic behaviour of brick masonry spandrel elements by describing typical behaviour modes and analysing the boundary condition of spandrel elements in URM walls. The main part of the paper concerns the development of simple mechanical models for estimating the peak and residual strength of brick masonry spandrels, which are supported either by a timber lintel or a shallow masonry arch. The proposed models are compared against results from experimental tests on four masonry spandrels. It is found that predicted and experimental values agree well.