- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 02 May 2018
Very broadly, foundations can be categorised as shallow foundations or deep foundations. Shallow foundations are typically used where the loads imposed by a structure are low relative to the bearing capacity of the surface soils. Deep foundations are necessary where the bearing capacity of the surface soils is insufficient to support loads imposed and so they are transferred to deeper layers with higher bearing capacity.
Pile foundations are a type of deep foundation. They are formed by long, slender, columnar elements, typically made from steel or reinforced concrete, or sometimes timber. A foundation is described as 'piled' when its depth is more than three times its breadth.
Pile foundations are principally used to transfer loads from superstructures, through weak, compressible strata or water onto stronger, more compact, less compressible and stiffer soil or rock at depth. They are typically used for large structures, and in situations where soil is not suitable to prevent excessive settlement.
The term ‘socket piles’ (or rock sockets), refers to a technique that is used to embed a pile into solid rock. This can be necessary to utilise the full structural capacity of the piles for both compressive and tensile forces. It is a technique that is typically used for offshore applications, such as drilling into a rocky seabed, where the depth is shallow or there is sloping solid rock.
The technique involves drilling into the rock layer to create a socket which is slightly larger than the pile. This creates a void around the outer edge of the pile which is filled with grout, usually Portland cement or an ultra-high strength grout depending on the structural requirements. This 'socket' in the rock provides the pile with stability by providing to resistance against lateral loads and uplift forces.
- The properties of the rock.
- The presence of fractures in the rock.
- The size and spacing of any fractures.
- The degree of weathering of fractures.
- The presence of any soil within fractures.
 Find out more
 Related articles on Designing Buildings Wiki
Featured articles and news
If it is not planned properly even simple a activity can kill.
A disgruntled or ignored stakeholder can easily derail your hard work.
Next generation cementitious materials
Still going strong...one of the great buildings of the 20th century.
Review of the bible for heritage assets and their management.
The David Lloyd Lymington Sports Village was 'Commended' in CIAT's 2018 AT Awards.
How do we make the smart city a reality?
Sir Nicholas Grimshaw has been awarded the UK’s highest honour for architecture.
Protecting the construction industry from Brexit.
Conceiving buildings collaboratively, testing them virtually.
Effective collaboration in post-disaster response and recovery