Anthony Rolfe - Q&A

Join us at the upcoming NZSEE conference, kicking off on April 19-21 where we’ll hear from New Zealand's leading earthquake engineers about the latest developments and solutions in their field.   

As a country located on a major fault line, it's crucial that we stay up to date on the best practices for designing and building infrastructure that keeps our communities safe.   

Anthony Rolfe, a geotechnical engineer at T+T, will be presenting at the conference. We spoke with Anthony, to learn more about his project work and how his valuable insights will be helping build a more resilient future in Aotearoa.   

 
You're speaking at the NZSEE conference, could you share more about your topic and what your presentation will cover? 

The topic I’m presenting is the mitigation of liquefaction-induced lateral spread ground displacements using an in-ground pile wall. 

In my presentation, I’ll cover a case study of a site where existing buildings are expected to be vulnerable to liquefaction-induced lateral spread ground displacements. Conventional solutions to improve building seismic performance aren’t always feasible when considering costs, and site constraints. This case highlights the value in considering non-routine engineering solutions.  

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

This in-ground pile wall solution aims to improve the seismic performance of existing buildings and to create more resilient structures. This relates to the conference theme of facing the seismic challenge as this solution tackles the uncertainties associated with the prediction of lateral spread. 

Liquefaction and lateral spread are challenging aspects of Earthquake Engineering. Could you tell us about the development of your in-ground pile wall solution? 

The in-ground pile wall extends along the seaward side of the site, away from existing buildings. This solution adds lateral restraint at a specific location (to the laterally spreading ground), which is expected to reduce lateral spreading.  

A displacement-based approach was used to estimate the additional lateral restraint required to achieve tolerable lateral spread displacements. This relates to the improvement of the existing buildings’ seismic performance.  

There are significant uncertainties in predicting lateral spread and actual displacements could be significantly more or less that estimated. 

A force-based approach was used to assess full passive pressure (from lateral spreading ground) being imposed on the in-ground pile wall.  This relates to  resilience, as the solution is required to have continued performance/maintain structural integrity for an extreme lateral spread event, i.e. very large ground displacements. 

What are the key benefits of using an in-ground pile wall?  

The main benefit of this solution is that it’s a cost-effective method of mitigating lateral spread displacements that also limits disruption to existing buildings and site activities. This means we can make these improvements critical to our community’s safety without, for example, having to shut down a school as this solution is applied there. 

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

The main benefit this case study provides the Earthquake Engineering field, and our communities, is that it encourages the consideration of non-routine solutions for existing problems. Through innovation and creative problem-solving, we’re able to provide a resilient design, helping build a safer New Zealand.