An investigation of the strength of brickwork walls when subject to flood loading

• Main Author: Herbert, Daniel Mark
• Published: Cardiff University 2013
• Subjects: TH Building construction
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.585313

The main purpose of this programme of research was to establish characteristic water levels to which new and existing properties of masonry construction can be protected against flooding. Typical flood protection systems often rely on the structural strength of the building and in doing so generate significant lateral loadings. Current guidance appears to be based on the results of a single experimental study and no calculation technique is currently available to determine suitable characteristic levels. The research aim was addressed by conducting a series of experimental tests at model scale and by developing a theoretical analysis. Model scale masonry wall panels were successfully tested in a geotechnical centrifuge and were subject to hydraulic loading or uniform wind loading. Wind loading was considered to allow validation of the experimental procedure to results in the literature. Wall panels were constructed from both brick and block units and the effect of different mortar strengths, openings, vertical loadings and cavity construction were assessed. The experimental procedure showed very good repeatability in terms of ultimate load and generally a yield line type failure mode was observed. A theoretical analysis based on yield line analysis was developed using spreadsheet software and verified using the results from the experimental programme. The analysis gave a good approximation of the experimental ultimate loads, but the optimised failure mode was not always consistent with that observed in the tests. A parametric study was completed to assess the effect of varying parameters not considered in the experimental study and in addition a typical domestic property was modelled to assess its resistance against flood loading. The characteristic water level for the weakest wall of the property was found to exceed the value given in the guidance, of 0.6 m, by 38 % and signified the importance of completing the correct modelling procedure.