our expertise

Geotechnical problems are often complex in their nature and solutions require balance and judgement. We approach every problem from First Principles to really understand the ground and anticipate how it will respond to what is to be built. That gives greater certainty. For us – and for our clients.

value engineering / optimisation

tunnelling

slope engineering

deep basements / foundations

ground improvement

temporary works

projects

Our team of specialists have experience in all major Infrastructure Sectors. Browse projects by sector or see all our projects.

Highway 23 Slip Repair

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Symphony Centre

An optimised retention solution that was music to the contractor’s ears

Barber Grove to Seaview Wastewater Treatment Plant Pipe Duplication

This project involved installing a new 1.2km-long, one metre diameter pressurised wastewater pipeline.

SH25A Taparahi Slip Remediation

McConnell Dowell with joint venture partner Fulton Hogan and designers Beca and Tonkin+Taylor completed the new Taparahi Bridge and reopened State Highway 25A in record time.

Mairangi Bay Pump Station

The existing Mairangi Bay pump station could no longer cater for the new development in the area and was overflowing onto nearby beaches.

We have worked with Andy and his team for a number of years now and we keep coming back to them as their approach to geotechnical design is always practical and efficient. They do not shy away from challenging designs and will always go that extra mile to make sure their designs are constructable.

Tim Pervan - Engineering Manager, Heron Construction

Over the past two and a half years, Andy and his team have consistently delivered innovative and efficient design solutions to a wide range of complex, geotechnically related, challenges on the City Rail Link Project.

Nigel McCreight - Engineering Manager, Auckland City Rail Link, Link Alliance

Andy O Sullivan had a great understanding of the contractors focus to provide a safe and efficient solution for the shaft works on the Saint Marys Bay Project. Their willingness to investigate change and be flexible during the construction phase allowed the project to realise opportunities and achieve a successful outcome.

Grant McLean - Senior Site Executive, McConnell Dowell

The Andy O’Sullivan team developed the design for the temporary works as part of the Barber Grove ECI. This included several aspects of geotechnical design from retaining structures to specialist considerations associated with TBM works. The AOS team provided practical and progressive solutions in a demanding geotechnical environment and as a result, the well-considered designs bought real value to the project.

Daniel Crichton - Senior Principal Engineer, Downer Group

Design and detailing of the soil – structure interaction for the Main Wharf North project was a considerable challenge for all involved. The ground improvement was required to stabilise the existing fill and alluvial soils, provide the majority of the lateral restraint for the entire wharf and back span slab in a highly seismic zone, all without excessive restraint of thermal and shrinkage actions. Andy and his team provided strong leadership in this complex interface, relentlessly driving efficiency and value in the solution.