Luke Storie - Q&A

As New Zealanders, we know that our beautiful country is located on the boundary of the Pacific and Australian tectonic plates, making earthquakes an ever-present natural hazard for us.  

That’s why it’s crucial to stay up-to-date with the latest developments in earthquake engineering. The upcoming NZSEE conference, starting on Wednesday the 19th of April, is the perfect opportunity to do just that.  

Luke Storie, a Geotechnical Engineer at T+T, will be speaking at the conference alongside Compusoft, a structural engineering company based in Auckland, about their collaboration and technical developments in earthquake engineering. We caught up with Luke to learn more about their work, how it's changing the geotechnical engineering space, and the key takeaways that can be applied to projects. 

 

You are speaking at the NZSEE conference, tell us about your topic and what your presentation will cover? 

The topic of our presentation is optimisation through an Alternative Solution approach incorporating soil-structure interaction. We collaborated with Compusoft, a structural engineering company, to develop this new approach. 

In our presentation, we’ll discuss a case study we worked together on using performance-based nonlinear time history analysis within an Alternative Solution approach. This involved not using code-based verification methods to validate the reinstatement of an earthquake-damaged building and instead reusing the existing foundation system.  

From a geotechnical perspective, we’ll explain how we were able to capture the uncertainty in the ground conditions and allow for the consequences of liquefaction to remove conservatism, creating an efficient superstructure design.  

It was through combining international best practices with NZ standards that together with Compusoft we were able to successfully deliver on this project. 

 

What led you to work on this solution together? Tell us about your collective skills, strengths, and how collaborating created this new approach. 

Collaboration was key to our approach. T+T's understanding of the ground model and the effects of liquefaction were critical to determining whether the existing piles could be reused. While Compusoft was able to accurately capture uncertainties in the structural model.  

We worked well together and were able to challenge each other while aligning our different skills and knowledge areas to successfully deliver an Alternative Solution approach. 

 

Why did you produce this solution? What are the current trends that led you to create this? 

We developed this Alternative Solution approach because reusing the existing piles required greater certainty in the building and foundation response. We achieved this through the consideration of the stress response in individual pile elements and founding soils, and understanding the performance of individual elements of the lateral load-resisting system in the structure. 

It’s common in engineering design for Building Code compliance to be demonstrated through the application of approved Verification Methods such as “B1/VM1” for general structural performance and “B1/VM4” for foundation performance. However, these verification methods are only generally appropriate for the design of specific buildings, with other approaches being more appropriate in the design of other more unique cases. 

Ultimately, even though an Alternative Solution approach may increase time and costs in design, it can have significant benefits to the construction efficiency, and design outcome, in this case allowing the existing piles to be re-used. 

 

How does this relate to the conference theme of 'Facing the Seismic Challenge'? 

Since the Canterbury Earthquakes, the urgency and awareness in New Zealand for more robust and resilient earthquake design outcomes has increased.  

With the recent release of the NSHM (National Seismic Hazard Model), our improved understanding of the seismic hazard means that we may be designing for larger levels of seismic shaking in parts of NZ in the near future. This challenges engineers to design more efficient systems with well-understood performance outcomes. 

Our case study presentation demonstrates how adopting an Alternative Solution approach can help us face this seismic challenge and deliver optimised outcomes. 

 

How will this help the Earthquake Engineering field and benefit our communities? 

By applying designs and assessments specific to the structures being assessed and streamlining procedures for seismic performance verification outside of the Verification Methods currently available, the earthquake engineering field and the wider community will benefit from more robust, resilient design outcomes that contribute to a safer Aotearoa.