A driven pile is a pile hammered into the ground to transfer the load of a building to a deeper, load-bearing soil layer. In areas with soft topsoil — such as clay and peat across large parts of the Netherlands — a building cannot be founded directly on ground level; the driven piles ‘seek’ a firm sand layer deeper in the ground.
How it works
A driven pile carries its load in two ways:
- End bearing — the pile point rests on a firm, load-bearing layer (usually sand)
- Positive skin friction — the friction along the pile shaft with the surrounding soil helps carry the load
The pile is driven into the ground with a hammer, via a pile-driving cap, until it reaches the required depth and bearing capacity.
Types of driven piles
- Precast concrete piles — prefabricated, reinforced concrete piles
- Cast-in-place piles — concrete poured on site into a bored or driven hole
- Steel tubular piles — for heavy loads or limited space
- Timber piles — mainly in older buildings
Points to watch
- Pile plan and calculation — number, length and type follow from a soil probe (cone penetration test) and structural calculation
- Negative skin friction — settling soil around the pile can exert a downward force; this is taken into account in the design
- Rot in timber piles — pile heads left dry (low groundwater) can lead to pile rot and foundation problems
Related terms
- Pile foundation
- Piling
- Pile-driving hammer
- Bearing capacity of a pile
- Soil investigation
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