Displacement-based seismic design of unreinforced masonry buildings

Displacement-based seismic design has been proved to be a rational procedure allowing the control of the inelastic response for both framed and wall structures under earthquake loading. Nevertheless, the application of this design methodology to masonry buildings still needs to be investigated. In this paper, a direct displacement-based design (DDBD) procedure for unreinforced masonry (URM) buildings is presented and critically compared to force-based design (FBD). DDBD was applied to a three-storey brick masonry building, which was assumed to be located in a high-seismicity site in Italy. Analysis results show that: (1) both the combination of horizontal seismic actions and non-zero accidental eccentricities may induce a significant increase and scattering in strength demands on URM shear walls, especially in near-field earthquake conditions; (2) after design optimisation, construction costs resulting from the proposed DDBD procedure may be about 30% lower than those provided by current code-based FBD procedures.