Earthquake design of unreinforced masonry residential buildings up to 15 metres in height

Abstract

The paper summarises the results of a displacement-based assessment (DBA) of the seismic capacity of typical load-bearing unreinforced masonry buildings between two and five storeys in height across a range of site sub-soil classes (B to D) and earthquake hazard factors (0.05 to 0.12), covering all of the capital cities and major regional centres in Australia. The study found that the DBA for out-of-plane bending of walls in the top storey of buildings identified far fewer cases of failure than did a traditional strength-based assessment. A similar trend was observed for the DBA for in-plane shear of walls at the ground storey of buildings. The DBA implied, for all practical purposes, that typical walls will have the in-plane shear displacement capacity to withstand the earthquake induced loads and displacements for any site soil conditions, and earthquake hazard factor up to 0.12. This contrasts with the corresponding strength-based calculations, which identified significant numbers of cases where failure would occur.