Seismic behaviour of "Simple Masonry Buildings" according to EN 1998

"Simple Masonry Buildings" (SMB), according to Eurocode 8, are buildings of a regular plan, which fulfil specifications depending on the system of masonry (i.e. plain, confined or reinforced). These buildings are expected to perform good seismic behaviour and explicit safety verification is not mandatory. In the present study the assessment of seismic vulnerability of one- and two-storey "simple buildings" of unreinforced brick masonry is performed by means of finite element elastic spectral analyses using as a failure criterion the value of the principal tensile stresses developed under seismic load combinations; failure will occur when the predicted principal tensile stress exceeds the tensile strength of masonry. Two buildings are analysed for various ground conditions and for ground acceleration, a, given from the Greek Annex for Seismicity Zone I. Herein the results are presented in tabular mode; for each wall, the maximum tensile stress, the fibre in tension (inside or outside), and the load combination that causes the stress, are presented. It is proven that the buildings behave very well under the imposed seismic actions and no damage is expected. For ground acceleration a(g.)S > alpha(urm,g), the construction of unreinforced masonry (URM) buildings is not permitted, but here these buildings are analysed and their seismic behaviour is compared with that of SMB. It is found that the expected damage is insignificant even if they are in high seismicity zones with ground acceleration equal to 0.24g.