Abstract:
Out-of-plane failures induced by earthquake loads are one of the most critical deficiencies of clay brick unreinforced masonry (URM) buildings. Despite a number of seismic improvement techniques having been previously investigated and applied, there is a significant lack of experimentally validated solutions that consider the viability of these interventions in terms of overall associated cost and practicality, and impact on the building tenants, aesthetics and heritage building fabric. The main objectives of the research presented herein were to develop and validate seismic securing techniques for URM walls that satisfied the above conditions, in consultation with industry representatives. Full-scale shake-table testing of two cavity and three double-leaf solid clay brick URM walls was undertaken. The vertical timber framing that is typically a non-structural support of the inner wall lining was used as part of the retrofit solution and was fixed to the wall with steel brackets and mechanical screw-ties in order to form a strong-back. Wall and retrofit construction details, test set-up, observed crack-patterns, peak ground acceleration (PGA), wall acceleration and displacement profiles at failure, and quantification of the improvement in seismic capacity associated with use of the proposed retrofit technique are presented herein.
