Deep Soil Mixing

Hiway Geotechnical is the largest provider of ground improvement technology in New Zealand.

Our deep soil mixing solutions use pioneering technology. The TurboJet and COLMIX techniques improve engineering performance on even the most problematic Geotechnical sites for a wide range of soil types.

Creating improved soil strength, deep soil mixing is the process of injecting and mixing a variety of binders with in situ soils to create columns of strengthened soil and binders. Designed to suit the specific soil and its intended application, injections are made from either grout slurry or dry binder systems.

Since introducing deep soil mixing technology to New Zealand over a decade ago, Hiway Geotechnical has held its position as the leading supplier of high performance, cost effective ground improvement technology.

Geotechnical DSM 2


Improvement to slope stability and slips.

Embankment strengthening and mechanical stabilisation of trenches and causeways, and embankments for rail, road, river or canal banks.

Reduced settlement control for structures.

Foundations of buildings with distributed load, e.g., rail or road beds, bulk material storing yards.

Foundations for light industrial buildings and residential building.

Containment of contaminated soils.

Impervious barrier walls.

Road slip repair.

Building foundations.

Liquefaction control and settlement prevention.

Shear key construction and earth dam foundations.

Retaining walls.

Foundation designs to mitigate liquefaction.

Deep Soil Mixing

The trusted name in deep soil mixing innovation, Hiway Geotechnical is New Zealand's largest provider of ground improvement technology.

Backdrop Geotechnical DSM


TurboJet and COLMIX technology is faster and more efficient than traditional methods, saving on construction time and materials.

Cutting edge technology minimises soil displacement and vibration.

Hiway Geotechnical’s equipment and expertise offer a solution to almost any engineering problem or material type.

Deep soil mixing capability reaching depths of more than 20 metres.

Quality control is guaranteed with onboard computer control and real-time data capture of drilling and grout parameters.

Comprehensive sampling, testing, and post construction testing verifies strength and quality.

Colmix Deep Soil Mixing

For a fast and effective solution to ground remediation, Hiway Geotechnical offers COLMIX deep soil mixing (DSM) technology. Regarded as the most reliable way to remedy slips, unstable slopes and liquefaction prevention, COLMIX deep soil mixing is backed up by Hiway Geotechnical’s engineering expertise.

COLMIX deep soil mixing is a fully automated system that utilises twin hollow augers to inject and mix cementitious grout into soils to achieve greater levels of strength. Each auger features a drill head tool with a grout outlet port to destructure the soil at the same time as binder is incorporated into it. Once the target depth is achieved, the direction of the augers is reversed allowing compaction of the columns for optimum soil and column interaction.

Colmix Deep Soil Mixing

TurboJET Deep Soil Mixing

Suitable for a wide range of applications, TurboJet is leading-edge deep soil mixing technology that combines the benefits of high pressure jet grouting and mechanical mixing. TurboJet achieves large capacity deep soil mixing and is proven as a highly efficient method of soil mixing. TurboJet strengthens in situ soils up to 3000 per cent to depths of more than 20 metres and up to 1200mm in diameter.

The high pressure cutting technique of TurboJet injects grout at several hundred bar pressure. Grout is injected through a series of outlet nozzles blending soil as the mixing tool advances. TurboJet is an ideal solution for problematic soils such as cohesive plastic clays.

As well as reducing construction time and costs, TurboJet provides improved performance over the traditional methods of piling, lightweight fill or pre-loading.

TurboJet Deep Soil Mixing
Geotechnical DSM strip


A commitment to innovation has seen Hiway Geotechnical position itself as the leading provider of solutions to complicated engineering scenarios in New Zealand.

Since first opening in 1986, parent company Hiway Stabilizers has cultivated a commitment to technical excellence and innovation. Today, Hiway Geotechnical sets the benchmark for deep soil mixing technology and performance. Our deep soil mixing performance has resulted in award recognition from the NZ Transport Agency, and our expert team of engineers have been responsible for the presentation of papers at local and international Geotechnical conferences.

Design & Project Management Services

Hiway Geotechnical offers a range of skills and expertise to manage your project from start to finish. We offer initial site appraisal as well as site investigation, project concept development, detailed design modelling, construction and full design certification.

Using Plaxis 3D finite element analysis, our design team configures the specific system and tools best suited to each project.