Soil Stabilisation & Ground Compaction
Uretek Soil Stabilisation & Ground Compaction to improve support for buildings, roads and other on-ground structures
The Uretek Method presents an effective answer in many cases where soil stabilisation is required to improve and assure sub-grade stability under existing on–ground structures including:
- concrete floors
- wearing surfaces such as
- paved airport runways
- bridge approach slabs
Uretek is not involved with soil stabilisation for agricultural soils, contaminated soils or purposes other than supporting on-ground structures.
SOIL STABILITATION 0F COHESIVE SOILS
The method traditionally used by Uretek involves injection of structural, expanding resin grouts into the ground. This is referred to as Uretek Deep-Injection.
This method is most effective where the sub-grade soils are cohesive. The resins and hardeners mix upon entering the ground and expand, to compact the adjacent soils and so increase their bearing capacity.
In cohesive soils the expanding Uretek resins are restrained by the adjacent soils and by the structure above. So the stabilising compaction takes place and remains under the structure that is being stabilised.
SOIL STABILISATION - AT VARIOUS DEPTHS OF WEAK STRATA
This compaction can be carried out at one or more depths, as much as 14m under the surface.
It is done where bore-logs reveal there to be weak strata. In certain conditions the bearing capacity of weak strata under structures can be increased this way by up to 500%.
SOIL STABILISATION - NON-COHESIVE SUB-GRADES
More recently the Uretek company has developed and patented a new technology, known as “Power Piles” to provide support to structures built on non-cohesive subgrades. (eg. sandy or muddy soils).
Whereas in the traditional Uretek Method the soil itself is compacted and the soil confines the lateral spread of the resins beneath the structure, the Power Pile unit in designed to confine the expanding resin, forming a virtual ‘pillar’ under the structure.
SOIL STABILISATION - IN CONJUNCTION WITH RAISING AND RE-LEVELLING STRUCTURES
Frequently Uretek soil stabilisation is carried out in conjunction with Uretek “Slab-Lifting” being used to raise and re-level the on-ground structure.
SOIL STABILISATION & GROUND COMPACTION - TO SUPPORT NEW HEAVIER LOADS
Uretek ground improvement may be applied under structures that are to support increased loads; for example when new, heavier machinery is to be installed into a factory, or when there is to be an addition to the building itself. In such cases it is preferable to apply the new loading before the Uretek procedure, as the increased weight will enable greater compaction to be applied and bearing capacity to be created.
Additional weight is sometimes applied temporarily to an existing structure for this purpose. For example when Uretek is being injected to re-level and re-support a railway bridge a locomotive is often positioned above that section to increase the load and further increase the bearing capacity.
Uretek stabilisation involves the compaction of soft soil layers to impede subsidence and so provide better support for structures on the ground.
Uretek employs these various methods of Soil Stabilisation and Ground Compaction
Raising and relevelling of on-ground structures, by injecting expanding geo-polymeric structural resins into the soil to be stabilised under the element to be raised. Injection of the self-expanding resins is through small, drilled holes (6mm or 16mm in diameter).
Soil stabilization and improvement ground bearing capacity is achieved by this patented technology that compacts foundation soils, again by similar injection through tiny holes but down to multiple depths in weak strata.
This patented Deep-Injection resin formulation brings to bear controlled forces of up to 10,000 kPa.
Patented, prefabricated elements are inserted through 34 or 38 mm Ø holes and expand up to 330 mm, allowing a concentration of ground compaction and soil stabilisation in a very defined volume. Structural versions of UPP’s give pile-like support with end bearing characteristics and skin friction.
SOIL STABILISATION IN NEW ZEALAND
In New Zealand, Uretek Ground Engineering and its associated companies employ various other unique methods of soil stabilisation and ground compaction in addition to those above.
These other techniques include Jet Grouting and Low Mobility Grouting.
An injection process delivering fluids to erode, mix with and stabilise in-situ-soils using engineered cement grout slurry.
This soil modification system employs high velocity cutting jets of cement grout in suspension from radial nozzles in pipes to erode the soil and mix with it to form a composite material.
LOW MOBILITY GROUTING (Sometimes simply called ‘Compaction Grouting’).
Grouting with cement slurry delivered via pipes to displace and compact the in-situ soils.
Mainmark Ground Engineering
Our wide range of modern technologies – including Uretek – solves many ground engineering problems
Fast, economical, long-lasting, environmental and with minimal disruption.