IN-PLANE FORCE DEMANDS AND PERFORMANCE OF DIAPHRAGMS
The Quake Centre brings together the best of academic research and industry knowledge focused on improved solutions from seismic research.
A major repercussion of the 2010/2011 Canterbury Earthquake sequence was the significant damage to concrete buildings in Christchurch, particularly those in the Central Business District (CBD).
Under the forces imposed by the quakes, the adequacy of current building design standards and construction technology, was seriously put to the test. The performance of a considerable number of buildings was found to be lacking, with severe damage and unexpected failure.
Des Bull, from Holmes Consulting Group LP, is currently undertaking research in this field. The research on In-plane Force Demands and Performance of Diaphragms, is in collaboration with Dr Didier Pettinga. The aim is to review a number of design methods in prediction forces, that develop in the structural floors of buildings during earthquakes.
“The diaphragms (floors and roofs) tie all the vertical structural components together. These vertical components resist lateral forces such as wind and earthquakes,” says Des Bull.
Des brings a wealth of knowledge and expertise in his field. He specialises in the structural design of reinforced concrete structures (buildings, bridges and wharves), with a strong background in earthquake engineering, investigation and research.
“With respect to earthquakes, structural designers are using a couple of methods to determine forces in the diaphragms, unfortunately, incorrectly,” says Des.
“The intended outcome of this research is to have a more consistent and improved method for estimating the forces entering and developing within floor diaphragms. This would be applicable to reinforced concrete and structural steel construction, for both new designs and the assessment of existing structures.”
The benefits of this research programme to industry is that it aims to develop and verify the best method for determining the size of lateral forces, and distribution of these forces for short, medium height and tall buildings.
It will continue to take industry-identified issues, engineering expertise and rigorous research to develop appropriate engineering results, to gain new standards in earthquake safety.
The Quake Centre is proud to support the research of Des Bull and Dr Didier Pettinga, in line with the overarching aim to improve seismic performance and community resilience.
Thank you to the Quake Centre and MBIE - their financial assistance helps to make this research possible.