Insights from a geotechnical engineer: Nick Traylen from Geotech Consulting

As a leading ground engineering company, Mainmark regularly collaborates with consultants from within the engineering sector including civil, structural and geotechnical engineers.

Nick Traylen is the director of Geotech Consulting, a geotechnical and geological consultancy based in Christchurch, New Zealand specialising in earthquake engineering, liquefaction and foundation engineering. Nick was a geotechnical advisor to the Ministry of Business, Innovation, and Employment (MBIE, formerly Department of Building & Housing) and chariman of the geotechnical section of the MBIE’s Canterbury Engineering Advisory Group, which helped guide the post-disaster recovery of Christchurch and the greater Canterbury region following the 2010 and 2011 earthquakes.

We recently spoke to Nick about his role at Geotech Consulting and why he chooses to work with Mainmark.

Ground engineering is a highly specialised industry, can you tell us about how and why you started working as a geotechnical engineer?

I studied at the University of Canterbury, obtaining a degree in civil engineering. After an early career with a mix of geotechnical engineering, structural engineering and hydrology, I moved to Hong Kong for a number of years where I focused on geotechnical engineering. Being a less prescriptive discipline, I found geotechnical engineering to be more of an interesting career path than, for example, structural engineering – however there are many opportunities for creativity in all branches of engineering.

Geotech Consulting Ltd was founded in 1992 and consists of myself and two other principals, Mark Yetton and Ian McCahon. We’re a small team with extensive local experience working on all aspects of geotechnical engineering including investigation, design, and review of foundations, seismic liquefaction, and ground improvement works across a wide range of projects.

Other areas we specialise in include land stability assessment and design; construction implementation for landslides and landslide damaged buildings; insurance claim assessments; and post-earthquake investigations and assessments for earthquake damaged buildings and land.

Since the 2010 and 2011 earthquakes, I’ve been heavily involved in high level advisory roles for government departments and local authorities. I’ve also co-authored a number of geotechnically-focused guidelines published by the New Zealand Government.

You’ve worked with Mainmark many times, what are some of the more recent projects you’ve completed with us?

The Christchurch Art Gallery was the project we are most proud of and collaborated closely with Mainmark. This complex job involved a two-stage plan to strengthen the foundation ground using jet grouting. We then re-levelled the structure using JOG Computer-Controlled Grouting to remediate earthquake damage to the building.

It was a ground-breaking project as it was the first large-scale building in New Zealand to have been lifted using this type of non-invasive technology and people were nervous about it. The outcome was successful and a boost for the Christchurch community and its recovery efforts, preventing this important building from being demolished.

Geotech Consulting Ltd has also collaborated with Mainmark on a number of other projects including the Resin Injection Ground Improvement Trials (the report is now available for review on the New Zealand Geotechnical Society website); the Northwood Supa Centre, which required ground improvement and re-levelling; 50 Carlton Mill Road, where we used jet grout columns to re-support the building; the Christchurch Town Hall bid where we proposed jet grout lattice work and ground improvement works; and a recovery feasibility investigation proposal for Lancaster Park using resin injection ground improvement.  We’ve also worked with Mainmark on the Victoria Mansions project using jet grout columns, the Holly Lea retirement complex where we used resin injection for ground improvement works, and currently the re-levelling of the seven storey West Fitzroy Apartments.

Is there a story you can share about working with Mainmark?

We’ve worked with Mainmark for many years. In the early days, we completed several smaller re-levelling projects prior to the Christchurch earthquakes. Then during the recovery efforts after 2011, I encouraged Mainmark to be more active. I assisted the government in assessing resin injection for inclusion in the official guidelines for home recovery efforts, and then for it to be more widely accepted and understood within the construction industry. It was during this time we needed to change the mindset that the only way to lift a building was by mechanical means, so the challenge was to overcome that thinking and demonstrate the viability of injection methods. I think it has since been well proven through the success of many lifting projects.

What has been your overall experience working with Mainmark, how do they operate differently?

Mainmark is a company that is willing to trial new technologies and invest money into research and development where necessary. Together, we’ve scientifically proven that resin can be used for liquefaction in the right soils – and it’s been well received around the country. International researchers from the United States and Italy have also recently returned to the Red Zone site to see first-hand how the soils have behaved during the trial conditions, as well as subject the injected resin panels to further large-scale dynamic testing. This has been an invaluable opportunity for us to showcase the technology and how it can be used for earthquake strengthening.

Mainmark also provides one of the few technologies that can be used to recover earthquake damaged buildings with minimal intrusion. The Supa Centa project for example, demonstrated that both re-levelling and liquefaction mitigation can be successfully carried out in a working business environment; Mainmark was able to successfully work around a fully operational supermarket with no business interruption.

Since the Christchurch earthquakes, have you noticed any changes in the way engineers (or other professionals) are doing things differently?

Yes, there a lot more engineers around to start with, and the standard of work has lifted due to a more collaborative professional environment and newer technologies, including solutions such as JOG.  There has also been a lot more engineering guidance from the New Zealand Government.

Looking forward, the inevitable downturn in work due to COVID-19 and the earthquake recovery efforts nearing completion, will have an impact on the industry. However, infrastructure spending in other parts of the country, including road projects, may partially offset this.

National road projects are the biggest investments for engineering services in New Zealand at the moment. School infrastructure is  another significant area of investment with the Ministry of Education continuing to roll out an ambitious building programme,  and hospitals are also an important sector earmarked for future projects.

How do you unwind away from work?

I’ve recently taken up golf again, now that the kids are a bit older. We also like to holiday on the West Coast at Lake Brunner. I enjoy tramping (hiking), spear fishing and free diving. Nature is a great escape.

Nick Traylen can be contacted via

By Claire Hartley

Claire is a strategic senior marketing and communications professional who joined Mainmark in 2015. She has extensive experience gained in a range of organisations across the APAC region and the UK; from large multinationals and start-ups to industrial B2B, IT and online businesses.