The damage caused by the 7.8-magnitude Kaikōura earthquake in November 2016 along the east coast of the South Island was unprecedented in New Zealand. On the other side of the Cook Strait, capital city Wellington was also badly affected.
Following the widespread effects, Cardno’s fast response and detailed topographical assessment and 3D modelling gave CentrePort Wellington a vital picture of the extent of damage.
When the earthquake struck CentrePort, the Cardno team was onsite within 24 hours to commence damage survey of ports and buildings. The large site posed many challenges, including dangerous unstable container stacks, ground fractures and holes, exposure to high winds, and changeable weather.
A traditional survey method may have taken days and put operatives at risk. To overcome these issues, Cardno used the advanced survey grade Falcon 8 UAV to perform a bulk data topographical survey with demanding accuracy requirements. This allowed us to assess the damage in detail and provide a baseline. Equipped with a professional grade camera and incredibly stable flight characteristics, the UAV could fly low and slow, capturing the terrain at an astonishing 10mm ground pixel width or ground sample distance.
We also implemented and monitored a precise Ground Control Network in combination with repeat aerial surveys to provide highly accurate 3D models and bulk topographical surveys capable of detecting ongoing settlement and deformation issues.
With this approach, our team took just a matter of days to provide a far denser pointcloud and extremely high-resolution aerial imagery of the entire site. Having early access to these visuals using a low-risk method was essential to enable crane inspections. With maps of height and horizontal movement across the port, visuals of large surface cracks and detailed imagery of cranes, CentrePort had an accurate insight into the extent of damage. Most importantly, it guided the short-term assessment of the disaster to inform the long-term planning and construction strategy.