Dynamic testing and analysis of adobe-mudbrick structures

Traditional, unreinforced adobe-mudbrick houses are highly susceptible to damage and destruction during seismic events. Research at the University of Technology Sydney has included shake table testing of 10 scale model (1:2) u-shaped adobe wall units to assess the performance of different reinforcement systems and evaluate the response to out-of-plane seismic forces. This paper describes the qualitative and quantitative performance of one unreinforced and two reinforced adobe structures. Results confirm the importance of using appropriately time-scaled input spectra to ensure dynamic similitude and induce damaging near-resonance conditions. The testing and analysis revealed both internally and externally reinforced structures to be effective at impeding initial cracking, as well as delaying major structural damage and ultimate collapse. The system incorporating external vertical reinforcement performed significantly better and has the clear advantage of being simpler to construct, as well as being a viable option for the retrofit-strengthening of existing dwellings.