Organized by SUZI and the Faculty of Civil Engineering, University of Belgrade, a lecture was held on December 12, 2018, by Prof. Andrew Charleson, Associate Professor at Victoria University of Wellington, New Zealand, titled “Recent New Zealand Earthquakes: Lessons and Emerging Challenges in Concrete Design.”
In his presentation, Prof. Charleson described and illustrated typical building damage observed during the 2011 and 2016 New Zealand earthquakes, with a particular focus on reinforced concrete (RC) structures. These structures sustained significant damage despite complying with design codes for that level of seismic intensity—without loss of life or structural collapse. However, most of the damaged buildings were later demolished. This was due to New Zealand’s earthquake insurance policies, which require that structural damage be repaired in a way that fully restores the building’s original load-bearing capacity. In this case, that was not possible because the RC structures had behaved in a ductile manner and experienced permanent plastic deformations.
The 2011 New Zealand earthquake is one of the few globally where RC buildings demonstrated highly ductile behavior, sustaining significant plastic deformations while avoiding collapse—even though the level of ground motion, in terms of spectral accelerations, far exceeded the design level. Notably, significant damage was observed in precast concrete floor systems within RC frame buildings that otherwise responded ductilely during the earthquake.
These earthquakes have led to a shift in thinking regarding performance objectives for building behavior during seismic events in New Zealand. A reduction in design ductility is being proposed, which would correspond to less damage during design-level earthquakes compared to previous standards. However, greater ductility and more significant damage may still be acceptable in more severe earthquakes, as long as collapse is avoided.
Lecture slides (in PDF) are available for SAEE members, with autorization from the author.
Organized by SUZI and the Faculty of Civil Engineering, University of Belgrade, a lecture was held on December 12, 2018, by Prof. Andrew Charleson, Associate Professor at Victoria University of Wellington, New Zealand, titled “Recent New Zealand Earthquakes: Lessons and Emerging Challenges in Concrete Design.”
In his presentation, Prof. Charleson described and illustrated typical building damage observed during the 2011 and 2016 New Zealand earthquakes, with a particular focus on reinforced concrete (RC) structures. These structures sustained significant damage despite complying with design codes for that level of seismic intensity—without loss of life or structural collapse. However, most of the damaged buildings were later demolished. This was due to New Zealand’s earthquake insurance policies, which require that structural damage be repaired in a way that fully restores the building’s original load-bearing capacity. In this case, that was not possible because the RC structures had behaved in a ductile manner and experienced permanent plastic deformations.
The 2011 New Zealand earthquake is one of the few globally where RC buildings demonstrated highly ductile behavior, sustaining significant plastic deformations while avoiding collapse—even though the level of ground motion, in terms of spectral accelerations, far exceeded the design level. Notably, significant damage was observed in precast concrete floor systems within RC frame buildings that otherwise responded ductilely during the earthquake.
These earthquakes have led to a shift in thinking regarding performance objectives for building behavior during seismic events in New Zealand. A reduction in design ductility is being proposed, which would correspond to less damage during design-level earthquakes compared to previous standards. However, greater ductility and more significant damage may still be acceptable in more severe earthquakes, as long as collapse is avoided.
Lecture slides (in PDF) are available for SAEE members, with autorization from the author.
