UC uses earthquake data to improve earthquake response

UC project uses earthquake data to improve earthquake response models for buildings

September 25, 2014

A University of Canterbury engineering research project is evaluating the methods and models used to predict the expected damage to multi-storey reinforced concrete buildings during earthquakes, using data gathered during the Canterbury earthquakes.

The project is part of the multi-year research project “Significant Advances for Earthquake Engineering” (SAFER), coordinated by UC structural engineering Professor Stefano Pampanin, from the Department of Civil and Natural Resources Engineering. It looks at refining the methods used to evaluate the performance of buildings subjected to earthquakes, with a view to developing and implementing practical and efficient building safety improvements.

“The impact on buildings from the Canterbury earthquake sequence has confirmed the complexity of reproducing and accurately predicting how buildings respond to earthquake motions,” Professor Pampanin says.

“Reproducing or predicting the seismic behaviour of portions of existing buildings under controlled conditions and simulated earthquake loading in a laboratory is already quite a challenging task. Dealing with the actual three-dimensional behaviour of real buildings, including structural and non-structural elements, foundation systems and soil conditions, subject to highly uncertain ground motions, is clearly an even more challenging task.

This research project involves comparing the outcome of diverse analytical and numerical (computer-based) models, from the most simple to the most complex, to the damage observed in a set of case-studies of reinforced concrete buildings from the Christchurch CDB,” Professor Pampanin says.

“As part of the ‘new normal’, existing buildings need to be evaluated using the best available methodologies to allow clients and insurers to make decisions about repairing versus demolition, or strengthening the building.

“While the best methods and models available are used, it’s a complex problem, and different assumptions at various steps of the many methods and approaches can lead to different answers. Common reference points or benchmarks are therefore vital.

“The more the various professionals involved in this area work together the better. With the data gathered during the Canterbury earthquakes, we have a unique and valuable opportunity to verify and improve the accuracy and usefulness of the various methods and models used to analyse building performance, and provide engineers with simple but reliable tools for everyday use.”

Third year UC engineering students Danny Garry and Henry Wakefield have joined the research team, which includes a strong international network. The pair experienced the Canterbury earthquakes at the start of their degrees, and have recently spent a full semester studying at Purdue University, one of the top five engineering universities in the United States.

“The experience at Purdue reinforced our appreciation for the fantastic international reputation and quality of the earthquake and structural engineering work carried out at the University of Canterbury. We got more and more enthusiastic about being able to work on a project like this that could lead to practical and important outcomes for society,” says Danny.

“Good benchmarking or cross-validation between engineers and other technical operators to agree and maintain consistency is very important. We chose this project as a unique opportunity to further our knowledge and help, not only with the Christchurch rebuild, but with the mitigation of seismic risk at a national and international level. It’s a great opportunity to look at this vital area in detail early in our careers,” says Henry.

The project has seen the pair devouring technical articles, guidelines, international codes, scrutinising engineering drawings and conducting numerous computer model simulations.

“There are no course readers or textbooks. This is a very complex area. In earthquake structural engineering there is no single mathematical equation that can provide you with the correct answer. It is a matter of having a holistic view and putting together all the evidence and information to draw conclusions and allow the end-user to make an informed decision,” says Danny.

Danny and Henry will present their findings to the University’s civil and natural resources engineering final year student research conference on campus next month.

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