Bearing capacity
The term 'bearing capacity' refers to the capacity of soil to support applied loads that are acting on it. In the construction industry, this typically relates to the capacity of soil to support building foundations, in which case, the bearing capacity can be calculated from the maximum average contact pressure between the foundation and the soil that would not produce shear failure.
Three modes of failure limit bearing capacity:
The ultimate bearing capacity of soil (qu) is the maximum pressure which can be supported without failure occurring.
The net ultimate bearing capacity (qnu) does not take into consideration the over-burden pressure and can be calculated as:
qnu = qu - Ydf
Where:
- Y = unit weight of soil
- Df = foundation depth
The net safe bearing capacity (qns) considers only shear failure, and can be calculated as:
qns = qnu / F
Where
The allowable bearing capacity (qs) is the ultimate bearing capacity divided by a factor of safety, and can be written as:
On particularly soft soil, significant settlement can occur without shear failure. In such instances, the maximum allowable settlement is used as the allowable capacity.
Karl von Terzaghi developed a theory for evaluating the ultimate bearing capacity of shallow foundations. His theory states that a shallow foundation is one where the depth is less than or equal to its width.
[edit] Related articles on Designing Buildings
- Bedrock.
- Building foundations.
- Dead loads.
- Floor loading.
- Force.
- Ground conditions.
- Ground improvement techniques.
- Ground investigation.
- Insitu testing of soils.
- Live loads.
- Lateral loads.
- Load bearing.
- Loadbearing capacity.
- Load-bearing wall.
- Moment.
- Moorfields building sets UK pile-loading record.
- Pile foundations.
- Pile integrity test.
- Point load.
- Settlement of buildings.
- Shear force.
- Stiffness.
- Structural engineer.
- Structural principles.
- Subsoil.
- Testing pile foundations.
- Topsoil.
- Types of soil.
- Types of structural load.
- Uniformly Distributed Load.
- Uplift forces.
Featured articles and news
Amendment to the GB Energy Bill welcomed by ECA
Move prevents nationally-owned energy company from investing in solar panels produced by modern slavery.
Gregor Harvie argues that AI is state-sanctioned theft of IP.
Heat pumps, vehicle chargers and heating appliances must be sold with smart functionality.
Experimental AI housing target help for councils
Experimental AI could help councils meet housing targets by digitising records.
New-style degrees set for reformed ARB accreditation
Following the ARB Tomorrow's Architects competency outcomes for Architects.
BSRIA Occupant Wellbeing survey BOW
Occupant satisfaction and wellbeing tool inc. physical environment, indoor facilities, functionality and accessibility.
Preserving, waterproofing and decorating buildings.
Many resources for visitors aswell as new features for members.
Using technology to empower communities
The Community data platform; capturing the DNA of a place and fostering participation, for better design.
Heat pump and wind turbine sound calculations for PDRs
MCS publish updated sound calculation standards for permitted development installations.
Homes England creates largest housing-led site in the North
Successful, 34 hectare land acquisition with the residential allocation now completed.
Scottish apprenticeship training proposals
General support although better accountability and transparency is sought.
The history of building regulations
A story of belated action in response to crisis.
Moisture, fire safety and emerging trends in living walls
How wet is your wall?
Current policy explained and newly published consultation by the UK and Welsh Governments.
British architecture 1919–39. Book review.
Conservation of listed prefabs in Moseley.
Energy industry calls for urgent reform.