Knowing asset vulnerabilities under earthquake conditions helped Port Nelson plan for a more secure future

Port Nelson Seismic Resilience Study

The 2016 Kaikōura earthquake in Aotearoa New Zealand caused significant damage to roads, rail lines and other infrastructure, and inflicted a heavy economic toll. Port Nelson Limited, an important seaport for Aotearoa and heavily relied upon to facilitate regional prosperity, realised it needed to be better prepared for the next earthquake. As well as being an export hub for forestry products, seafood and wine, it's the largest seafood processing port in Australasia.

Seeking geotechnical expertise to gain understanding of their seismic vulnerability in earthquakes, Port Nelson wanted to know what assets were most susceptible to damage and to what extent in varying strengths of earthquake? With this knowledge, they could update their emergency management plans to integrate the expected performance of critical structures, such as wharves, in earthquake events.

We performed site investigations comprising boreholes, cone penetration and laboratory testing, and geophysical surveys. We assessed the seismic performance of Port assets through behaviour of soil materials under different shaking levels, examined by numerical modelling. And we created computer simulations with nonlinear dynamic analyses using advanced plasticity models for various soil layers. By understanding soil-structure interactions, we could gather each asset's seismic resilience. The study also aids future design and informs construction planning, supporting a more secure future for the Port and the region.