GDL Piling Ltd offer a range of techniques for the installation of foundation-bearing piles for large structures and buildings along with different types of piled retaining walls. Our piling techniques include Large Diameter Rotary Board Piling (LDP Piling, and Contiguous Flight Auger Piling (CFA Piling).
What is a Pile Foundation?
A pile is a long cylinder of a strong material such as concrete that pushes into the ground to act as a steady support for the construction of buildings on top of it.
A pile foundation is a solution for the following situations:
1. When there is a layer of weak soil at the surface this layer cannot support the weight of the building. If this situation arises, the loads of the building have to bypass this layer and transfer to the layer of stronger soil or rock that is below the weak layer. A pile foundation facilitates this requirement.
2. For structures such as high-rise buildings, bridges or water tanks where there are very heavy and concentrated loads.
A pile foundation is capable of taking higher loads than spread footings.
The two fundamental types of pile foundations – an end bearing pile and a friction pile which are based on structural behaviour and each one works in its own way.
End Bearing Pile
An end bearing pile sees the bottom end of the pile resting on a layer of especially strong soil or rock. The load of the building transfers through the pile onto the strong layer to allow this pile to act like a column. The key principle is that the bottom end rests on the surface, which is the intersection of a weak and strong layer. The load therefore bypasses the weak layer and is safely transferred to the strong layer.
A friction pile works on a different principle. This type of pile transfers the load of the building to the soil across the full height of the pile by friction. In other words, the entire surface of the pile, which is cylindrical in shape, works to transfer the forces to the soil.
How does Pile Construction take place?
Our in-house design team can advise on the selection of the most appropriate pile type for your project, as well as produce detailed designs for the installation and validation of the works.
We use two different approaches with the appropriate method for the installation of piles depending on the type of piles required for a project.
• Driven piles (concrete piles / steel piles)
• Auger displacement piles
• Driven cast in–situ piles
• Rotary-bored piles with temporary casing, LDP (large diameter pile)
• Continuous flight auger (hollow stem).
Regardless of the pile installation method, groups of piles are connected together by a series of ground beams and a pile cap to transfer the load from the structure to the head of each pile uniformly.
Additionally, groups of bored replacement piles are arranged in order to construct piled retaining walls, which can be the preferred solution for construction of deep basements and shafts. Particularly in instances where ground conditions and / or sensitive adjacent structures preclude the use of sheet pile.
We frequently undertake piling contracts as a specialist contractor, alternatively we can offer an integrated approach by combining piling with those other services offered by the wider GDL Group such as earthworks and ground improvement. When the geotechnical or the enabling element is significant, we have the capability to undertake projects directly for a client as the main contractor.
We operate a fleet of specialist piling rigs from leading manufacturers, which are both versatile and have the capabilities required to carry out a wide range of installations.