Solutions
Ground improvement, piled foundations, retention, seismic strengthening, geoenvironmental treatment — purpose-built equipment providing solutions across the full spectrum of ground engineering.
New Zealand's ground engineering challenges are as varied as its geology. Soft alluvial soils beneath urban developments, variable fill on brownfield sites, liquefiable ground in earthquake-prone cities, steep terrain requiring piled foundations, and ageing bridge infrastructure demanding rehabilitation — these are the problems that GSI NZ's Ground Engineering division is built to solve.
Our Ground Engineering capability covers the full spectrum of foundation, retention and ground improvement techniques — from CFA piling and deep soil mixing to jet grouting, in-situ trench mixing and contaminated land treatment. What makes our approach distinctive is that all of this is delivered by a single integrated team of geotechnical engineers and geologists, and specialist construction crews, operating purpose-built ground engineering equipment that can work in locations where standard plant cannot.
WHY GSI NZ
Step 1
Ground investigation defines soil conditions, bearing capacity, and structural requirements. Our engineers design the ground improvement solution, specifying treatment depth, and installation parameters to meet the project's load and access constraints.
Step 2
The specialist mixing equipment is mobilised to site. Ground improvement is carried out with real-time monitoring using on-board computer systems recording drilling parameters. Construction is delivered by GSI's specialist and highly experienced Ground Engineering crews.
Step 3
All testing is overseen and delivered by GSI with the use of independent consultants, sub-contractors and certified laboratory testing. As-built records confirm ground improvement construction and performance. A completion report with all QA documentation is provided on handover.
Low-vibration continuous flight auger piling for foundations, retaining walls, and slope stabilisation. FD45 restricted-access rig, 450—600 mm diameter to 20 m depth.
Continuous stabilised trench walls 550—950 mm wide to 16 m depth, first deployed in New Zealand by GSI.
EQUIPMENT
Our In-Situ Trench Mixing system — the first of its kind deployed in New Zealand — forms continuous stabilised trench walls 550—950 mm wide to 16 m depth without excavation or spoil removal. The technology is well established in Europe and North America for cut-off walls and groundwater barriers, and GSI NZ brought it to New Zealand to address applications that were previously impractical or uneconomic for the local market. Ground Engineering solutions are frequently combined with our Geohazard Engineering and Specialist Grouting divisions on the same project — giving clients a single integrated team across all ground-related challenges.
GSI NZ's ground engineering capability was significantly strengthened through the 2019 acquisition of Hiway Geotechnical, which brought CFA piling, jet grouting, in-situ mass stabilisation, and in-situ trench mixing under the GSI roof. That acquisition expanded our offering from geohazard response into comprehensive ground engineering across New Zealand — and today our Ground Engineering division operates alongside our Geohazard Engineering and Specialist Grouting divisions on the same project when the scope demands it. Every project is fully documented — QA records, as-built drawings, and testing results provided on completion.
GROUND ENGINEERING
CFA piling and GCS wall on a constrained coastal site in Auckland.
View Project →SPECIALIST GROUTING
126 soil-cement columns to stabilise an active landslide mass — Central Hawke's Bay.
View Project →SPECIALIST GROUTING
Ground improvement and foundation works for major Christchurch aquatic facility.
View Project →Get in Touch
From urban piling to mass stabilisation, our in-house engineers design and build every solution. One contract, one team, no gaps.
Talk to an Engineer