Mass Stabilising

Mass stabilising is a highly efficient way to improve very low strength, high moisture soils. Hiway Geotechnical’s expertise has seen us carry out the stabilisation of a wide range of high moisture content soils including alluvium, peats and contaminated soils.

In New Zealand, mass stabilisation is a relatively new technology. Always at the forefront of ground improvement innovation, Hiway Geotechnical first introduced mass stabilisation to New Zealand in 2005 and is now regarded as the industry expert in the field.

Dry binders consisting of a single substance, or a mixture of binders, are hydraulically pumped at pressure to provide a full treatment of the soil up to a depth of 5 metres. A high-pressure tank is used for binder pumping and delivery. In the past, quality mixing of binder has been difficult to achieve but Hiway Geotechnical’s computer controlled technology allows load cells on the tank to accurately control, measure and record binder delivery to ensure target application rates are achieved. In addition, Hiway Geotechnical utilises state of the art GPS positioning controls to ensure accuracy and consistency of the treated materials in the defined stabilised cell area.

Wet grout binders can also be applied to mass stabilisation injected into the ground at low pressure and blended with the existing soils to provide a homogeneous cement-soil matrix.

Hiway Geotechnical’s stabilisation methods have been instrumental in the rebuilding of Christchurch following the earthquakes. Our design and project team has provided solutions for both in situ and ex situ stabilisation of foundations.

Geotechnical Mass Stabilisation


Increase the strength of soft soil.

Improve the deformation properties of soft soil and reduce settlement.

Increase dynamic stiffness of in situ material.

Remediation through immobilising contaminants.

Improve the stability of embankments or slopes.

Temporary and permanent retention solutions.

Water cut off barriers.

Mass Stabilisation

Pioneering mass stabilisation since 2005, Hiway Geotechnical has the expertise and experience to deliver robust results.

Backdrop Geotechnical Mass Stabilisation 1


In situ stabilisation saves on material and energy costs.

Removes the need for costly dewatering, below ground retaining walls and dig out and replacement methods.

Engineering properties of the soil are improved, allowing soil to be linked with surrounding structures without harmful settlement differences.

Removes the need to dispose of soil resulting in less transportation and traffic pollution.

An efficient process that allows treated soil to be reused as structural fill.

Provides a rapid ground improvement method that is adaptable to a wide range of soil conditions.

In situ stabilisation

Hiway Geotechnical’s in situ mass stabilisation is a fast and effective way to permanently strengthen high moisture, low strength soils.

More effective than traditional shallow in situ stabilising, Hiway Geotechnical’s in place stabilising creates a stabilised block by mixing dry binders or slurry grout with in situ soils. Cement blend binder is pumped through a rotary mixing head and injected through the soil to provide a 100% treated block. Computer controlled delivery ensures quality control by monitoring binder flows and tonnage as well as accurately ensuring consistency of the mixed area through 3D GPS positioning of the mixing head.

Suitable for a range of soil conditions, in situ stabilisation achieves mass stabilising to a depth of 5 to 6 metres. The result is improved performance of the Geotechnical properties of the soil.

Mobile equipment offers a cost effective solution that removes the need for costly dewatering and saves on the cost of bringing in new materials and disposing of unsuitable materials to landfill.

Hiway Geotechnical’s in situ mass stabilisation has been adopted by the Christchurch rebuild team as an acceptable method for constructing house foundations (Type G2b) in accordance with MBIE guidelines.

Geotechnical insitu stabilisation 3

Ex situ stabilisation

The excavation, treatment and replacement of low strength soils is made easy with Hiway Geotechnical’s ex situ specialist equipment. Low strength soils are given improved stability, impermeability and load-bearing strength.

Hiway Geotechnical’s Reterra soil recycler is a purpose-built mobile soil stabilising plant and represents the latest technology in controlled mixing and soil improvement. A wide range of soils and aggregate can be put through the machine and mixed with stabilising binders. The process delivers significant cost savings by removing the need to bring in new soil or dispose of existing soil.

Hiway Geotechnical’s ex situ mass stabilisation has been widely adapted for the rebuilding of Christchurch following the 2011 earthquakes. In Christchurch, soil is comprised largely of sand, silt and gravel and the stabilisation process has provided solid ground suitable for rebuilding structures and homes. 

Geotechnical Mass Stabilisation strip


Since 1986, Hiway Stablizers has been at the forefront of pioneering stabilising technology. Applying this same dedication to innovative thinking and technology, Hiway Geotechnical has set the industry standard for stabilisation works. Computerised equipment ensures full analysis and control to deliver quality and robust performance.

Design & Project Management Services

Ground improvement and stabilisation is a complex, specialist field. Working with Hiway Geotechnical, you are reassured by our reputation as an organisation that has set the benchmark for ground improvement technology in New Zealand. Our team has significant experience working on many challenging projects including the Christchurch rebuild, contaminated mine sites, and major infrastructure works.