Stepped foundation
Foundations provide support for structures, transferring their load to layers of soil or rock that have sufficient bearing capacity and suitable settlement characteristics.
Strip foundations (or strip footings) are a type of shallow foundation used to provide a continuous, level (or sometimes stepped) strip of support to a linear structure such as a wall or closely-spaced rows of columns built centrally above them.
Where the natural surface of the ground is sloped, the most economical solution may be a stepped foundation. In this case, the foundation takes the form of a series of concrete horizontal steps following the slope of the ground.
This helps to minimise the amount of excavation and below-ground wall construction that would otherwise be required. Stepped foundations can also be used to transition from deep foundations to shallow foundations, and at corners and intersections.
Regularly stepping foundations also avoids abrupt and excessive changes in level that could cause a weakness resulting in movement. Similarly, abrupt and excessive changes in foundation depths should be avoided at corners and intersections by the introduction of stepping.
Each step in the foundation should be no higher than the thickness of the foundation. The foundation at the higher level should also overlap the lower foundation, typically by at least twice the height of the step, or by the thickness of the foundation, or by at least 300 mm (whichever is greatest).
Drainage must be carefully designed to eliminate the danger of instability due to accumulating water pressure.
[edit] Find out more
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
About the 5 Percent Club and its members
The 5% Club; a dynamic movement of employers committed to building and developing the workforce.
New Homes in New Ways at the Building Centre
Accelerating the supply of new homes with MMC.
Quality Planning for Micro and Small to Medium Sized Enterprises
A CIOB Academy Technical Information sheet.
A briefing on fall protection systems for designers
A legal requirement and an ethical must.
CIOB Ireland launches manifesto for 2024 General Election
A vision for a sustainable, high-quality built environment that benefits all members of society.
Local leaders gain new powers to support local high streets
High Street Rental Auctions to be introduced from December.
Infrastructure sector posts second gain for October
With a boost for housebuilder and commercial developer contract awards.
Sustainable construction design teams survey
Shaping the Future of Sustainable Design: Your Voice Matters.
COP29; impacts of construction and updates
Amid criticism, open letters and calls for reform.
The properties of conservation rooflights
Things to consider when choosing the right product.
Adapting to meet changing needs.
London Build: A festival of construction
Co-located with the London Build Fire & Security Expo.
Tasked with locating groups of 10,000 homes with opportunity.
Delivering radical reform in the UK energy market
What are the benefits, barriers and underlying principles.
Information Management Initiative IMI
Building sector-transforming capabilities in emerging technologies.
Recent study of UK households reveals chilling home truths
Poor insulation, EPC knowledge and lack of understanding as to what retrofit might offer.
Comments
What are the rebar design standards for stepped footing rebar?
are 90 degree hooks at step down acceptable?