Shaky ground: EQC funds motion research

27 January 2023

A new modelling technique being pioneered in New Zealand and funded by the Earthquake Commission (EQC) could be used worldwide to improve the seismic resilience of buildings.

University of Canterbury Researcher Felipe Kuncar is working on a ground-motion simulation model that will help predict earthquake damage depending on the soil beneath buildings, and will better inform engineers and make buildings more resilient to large earthquakes.

Head of Research Natalie Balfour says EQC is proud to support “the next frontier of seismic hazard analysis”.

“Different soils respond differently in earthquakes. It’s really exciting to be building this understanding about ground shaking at such a local level — it means we can plan and build smarter and be better prepared,” she said.

In coming months, Mr Kuncar expects to include feedback from more than 50 motion sensors, or accelerometers. By combining this data from frequent, smaller earthquakes with larger earthquakes, the model can better simulate how a big earthquake would affect a neighbourhood based on the make-up of soil.

Mr Kuncar says Christchurch offers a unique scenario as it has a high number of accelerometers producing large quantities of real data from big and small magnitude events.

“The important step is to validate the computer simulations with real-life observations,” he said, adding that building codes currently incorporate soil in only in a “simplistic way.”

“We hope to improve this practice, and think these simulations will be the future of earthquake resilient design.

“The soil is a softer material than the rock beneath it, and as a result it tends to amplify the ground shaking. If you shake a plate of jelly, the movement will be more severe at the top of the jelly than on the plate itself,” Mr Kuncar said.

The research is expected to be extended to Wellington, Napier and other regions featuring good data about the soil. The modelling approach could eventually be used all over the world.