Advantages of the Helical (screw) pile
GTL’s Helical (screw) pile foundation is predominantly known for its ease and speed of installation.
Some of the advantages are: (please click on one for more information)
-
Speed of installation...typically a standard 6m pile takes on average ten minutes to install. This reduces contract program time, on site prelims, speed to market and road/track closures and operational downtime amongst other factors.
-
Sustainable and environmentally friendly...by reversing the installation process the Helical (screw) pile can be decommissioned and re-used leaving a Greenfield site. The product can also be recycled.
-
No spoil...with the spiraling cost of muck away the solution proves to be financially and environmentally viable especially in contaminated ground.
-
No Concrete...no curing time so loads can be applied immediately. A 60m mast foundation can be installed within one day.
-
Less disruption...Reduced deliveries unlike the wet trades, means less disruption to neighbours and other on site activities.
-
Workmanship...not so reliant on skill of driver. Minimum Instruments required monitoring pile installation thus reducing errors and problems of calibration.
-
Waste...minimal materials wasted. Waste can be recycled. Off site pre-fabrication of piles and grillages reduces site waste and disposal costs.
-
Program acceleration...If program requires acceleration then this can be achieved quickly by deploying additional installation equipment and materials.
-
Minimal Soil Disturbance...due to installation method unlike CFA or Rotary Bored. Especially through sand and gravels.
-
Reduced Negative Skin Friction...Helical piles have an advantage in providing reduced negative skin friction in soft clays, as the stem diameter is smaller than the flight diameter. This gives a larger pile capacity compared with other pile systems.
-
Adaptable...Pile can be tailored to suit the ground conditions from cohesive (clays) to cohesionless (sands and gravels) soils or a combination of both.
-
Reduced resource...a typical crew consists of three. An advantage on hazardous sites where mitigating risk is paramount. It also allows GTL to provide up to 85% national content.
-
Guaranteed product...quality control of steel and fabrication gives confidence in the quality of the pile in the ground prior to installation.
-
End Bearing...the steel helix plate gives you very good end bearing characteristics, with very little re-moulding of the soil surface due to installation.
-
Flexible...Helix plates can be spaced to give particular failure conditions (end bearing or shaft).
-
Comparable...Monitoring of soils quality and capacity via torque transducer during installation, provides a direct comparison to available site investigation and preliminary pile tests.
-
Soil variability - ...Unforeseen variability in soils can be overcome by the addition of helical plates and pile sections.
-
Quick test results...Preliminary Pile tests and results can be carried out and received with 48 hours of starting test setup.
-
On site Modifications...Variability in penetration depth is achieved by additional pile sections.
-
Reinforcement cages...do not require reinforcement cages which eliminates the inherit associated problems.
-
Close proximity...to trees, services, existing foundations and buildings. No root damage or undermining.
-
Resistance to tension and compression...the pile can be used as a tension anchor and soil nail.
-
Restricted access...Segmented sections for reduced head heights – piles can be installed under pipe racks and in basements.
-
Cold temperature conditions...unlike concrete that can only be installed above freezing point without specialist equipment.
-
Underwater Installation...by utilising specialist GTL equipment Helical (screw) piles are able to be installed in subsea marine conditions
-
Low mobilisation/demobilistation costs...equipment is delivered by a low loader
-
Corrosion...within aggressive soils can be accommodated
-
No liners/casings...no requirement for piling through perched water tables or underground water courses.
-
Defects...as concrete is not being used, the risk of inherent defects caused by necking (e.g. high ground water table ground conditions) or bulging is eliminated
-
Integrity - ...No integrity testing is required
-
Obstructions/Services...If obstructions in ground occur (e.g. Fill) unlike other piling systems, screw piles can be removed and reinserted again
