About Piling
Piling can be used in certain situations where it is not safe, practical or economical to excavate for traditional foundations.
This may be due to:
- the nature of the ground, eg loose backfilled ground, water bearing soils, soft clays incapable of taking any significant loading
- local influences such as deep penetrating tree roots in shrinkable clay soils leading to desiccation of the upper layers.
The basic function of the pile is to transfer the building load to greater depths to achieve the required load bearing capacity, thus overcoming the problems in the upper stratum.
Purkelly can design and construct piles or complete foundation solutions consisting of piles and beams or raft slabs to suit almost any site conditions with the minimum fuss and disruption to the owner or builder.
All of Purkelly's piling equipment is designed for use where there is restricted access or limited headroom. It will operate within domestic properties if required, and is also powerful enough to compete with larger machines when working in open sites.
Let Purkelly design and construct your foundation package, or if you already have a design and a groundworker on board, we will happily construct the piles only. Purkelly piling services offer:
Economy:
Engineered solution to provide maximum value for money.
Speed:
Purpose designed machinery and experienced professional teams ensure excellent productivity rates.
Health & Safety:
No deep trenches posing risks to operatives, occupants and visitors to site.
Environmentally Friendly:
Piling is designed to use a minimum amount of materials, ie concrete and steel and produces very little spoils. The environment benefits from reduced energy usage in materials production, reduced vehicle movement in transporting material and spoil, and reduced excavation results in less spoil to go to landfill sites.
Some of the pile types that Purkelly offer include:
Our T5000 Auger Drill Rig is a versatile self propelled drill rig with variable track motors and track width providing exceptional manoeuvrability.
1. Auger bored piles
These are used in cohesive clay soils where there is no groundwater and the bore remains dry and open on completion.
This type of pile takes it load bearing capacity from the friction generated between the clay and the surface area of the pile shaft, and therefore different loading bearing capacities can be achieved by varying the diameter and length of the piles.
In shrinkable clay soils that are likely to be affected by the action of tree roots, the upper 3-4 m of pile can be sleeved to help reduce the affects of "ground heave".
The type of loads that these piles are capable of carrying are: |
|
Diameter |
Load Capacity |
200 mm |
up to 90 KN |
250 mm |
up to 160 KN |
300 mm |
up to 200 KN |
Auger bored piles can also be used to form retaining walls by forming a series of piles with a minimal gap between them. This is known as a contiguous piled retaining wall and can be a useful tool in the formation of basements, swimming pools, etc.
Purkellys in-house chartered civil engineer will design the piles to suit the loads, ground conditions and applications on each project.
Our self propelled driven pile rig with variable tracks is a stable and reliable rig suitable for many contracts where steel cased driven piles are specified.
2. Steel-cased Driven Piles
These piles are used in situations where an open bored pile cannot be used:
- due to loose ground conditions such as backfilled or made ground overlying a decent bearing stratum
- where there is groundwater present
- if the soils are too soft or weak to achieve the friction required to carry the loads required.
This pile is formed by driving a steel tube, crimped at the leading end, down through the problem ground into denser stratum below capable of carrying the load. The tube is driven by means of a vibratory air hammer or a drop weight and is driven to a pre-determined set, eg 3 mm per drop weight blow or 25 mm per minute in the case of the vibratory hammer. Steel reinforcement is then placed into the tube and the tube filled with concrete to form the completed pile.
Driven piles are end bearing and thus derive their load bearing capacity mainly from the density of ground in which a pile terminates. Obviously the capacity also increases with diameter.
Typical load bearing capacity of the driven piles Purkelly offer are: |
|
Diameter |
Load Capacity |
150 mm |
90 - 100 KN |
220 mm |
150 - 180 KN |
As in the case of bored piles, our engineer will design the piles required for any particular project.
