Bearing Capacity
Definition
The maximum stress a soil or rock can sustain beneath a foundation without shear failure. Expressed as ultimate bearing capacity (at failure) and allowable bearing capacity (with a factor of safety applied for design).
- Defines
- Max stress a soil or rock bears without shear failure
- Ultimate form
- Stress at failure
- Allowable form
- Ultimate value reduced by a design safety factor
- Relevance
- Foundation and structural-collapse investigations
Common questions
How does bearing capacity factor into a collapse investigation?+
If the load a foundation actually transmitted exceeded the soil's allowable, or even ultimate, bearing capacity, that mismatch is examined as a possible root cause, often alongside construction quality and design load assumptions, rather than treated as the sole explanation.
What field or lab data is used to establish bearing capacity after the fact?+
Investigators typically rely on standard penetration test records, soil borings, or geotechnical reports from the original design phase, then compare the design assumptions against site conditions such as groundwater level and soil type observed post-failure.
Related terms
- Cone Penetration Test (CPT)
- A continuous in-situ test pushing an instrumented cone through the soil and measuring tip resistance and sleeve friction. Provides a nearly continuous...
- Differential Settlement
- Non-uniform vertical movement of different parts of a foundation, distorting the structure it supports. More damaging than uniform settlement because it induces...
- Liquefaction
- Loss of shear strength in saturated granular soil when earthquake-induced cyclic loading causes pore water pressure to equal the total stress, reducing...
- Piping
- Internal erosion in an embankment or foundation in which seepage flow progressively removes fine particles along a concentrated flow path until a...
- Standard Penetration Test (SPT)
- An in-situ test measuring the number of blows to drive a split-spoon sampler 300 mm into the soil at a given depth....