Rocking wall systems have huge potential in post-quake Christchurch

The Quake Centre Scholarship Programme is supporting a research project to investigate the performance of reinforced concrete coupling beams in coupled wall systems, subject to axial restraint. The project is being carried out jointly by the University of Auckland and the University of Canterbury.

University of Auckland Masters student Richard Malcolm is undertaking the research, under the supervision of Jason Ingham at UoA and Des Bull at UoC. The project is using finite element analysis software in order to better understand how the axial restraint provided to coupling beams by the adjacent structural components affects the performance of the entire coupled wall system.

The origins of the research began with the Canterbury Earthquakes Royal Commission enquiry, which identified the undesirable behaviour of several coupled wall systems, potentially as a result of a lack of consideration of the axial restraint effects on the coupling beams.

In its findings the Commission recommended that the behaviour of coupled walls be investigated further. Because coupled wall systems are a common lateral resistance system of tall buildings, and in particular in buildings with shear cores, the performance of the coupled wall system is an important aspect of seismic design in New Zealand.

With the support of the UC Quake Centre, Richard is hoping that the research project will provide a better understanding of the performance of coupled wall systems, subject to realistic restraint conditions. The outcomes are intended to provide design guidance to practicing engineers and advice to future design code amendments. The performance of coupled walls can then be better understood and accounted for in future designs, thus improving the reliability of coupled wall systems in the event of seismic activity.