Nz earthquake

Aecom associate director in ground engineering Jamie Codd moved to New Zealand in 2011, after the main Christchurch earthquake. He said that Wellington – the ...

In fact, the 2016 Kaikoura earthquake already caused significant liquefaction in the Wellington Port area and an equivalent earthquake closer to Wellington will probably do that once more, but on a larger scale. The lesson from Christchurch to try to prevent building on liquefiable soils cannot be applied to the existing areas of Wellington anymore and what is left is to apply measurements to minimize the risk and damage in Wellington in case of an earthquake. This is a similar idea to car suspension and sees the superstructure of a building decoupled from its substructure, isolating it. There is a 400mm seismic gap to allow for this movement – during the 2016 earthquake it “slid” around 15-20mm. Te Papa’s base isolation system takes the form of 152 flexible bearings, described as a “rubber-and-steel sandwich with a core of lead”, that sit between the main building and the concrete slab of its foundation. “One could imagine, for instance, to reserve the most liquefiable areas for sports fields or parks rather than residential areas, and build new residential areas on less sensitive areas. One technology to reduce earthquake impacts on buildings, pioneered by New Zealand scientist Dr William Robinson in the 1970s, is what’s known as base isolators or a base isolation system. Meanwhile, one critical piece of infrastructure that was damaged in the 2016 Kaikōura quake was State Highway 1, the country’s longest and most used road. That was in 2012 to 2013, so they’ve had several years to retrofit those buildings and apply new technologies.” The transport corridor north and south of Kaikōura suffered extensive damage and was inundated by numerous rockfalls and more than 750,000m3 of debris from 85 landslides. This has seen them construct the Transmission Gully Motorway, a new 27km road that stretches past Wellington with the express purpose of improving safety and offering better access. “They know which roads would be affected, which lifeline infrastructure would be affected, and then respond to them.