Bearing Capacity and Types of Failure PPT Flashcards
In order to avoid a bearing failure of the footing, in which the soil beneath the footing moves downward and outward from under the footing, __________. This limitation is provided by ensuring that the __________.
- The service load stress under the footing must be limited.
- Service load stress, qs, is less than or equal to an allowable bearing capacity, qa.
Computation of Ultimate Load
qu = Pu / Af
This type of failure is also referred to as Punching Shear Failure
Diagonal Tension Failure
The footing fails due to the formation of inclined cracks around the perimeter of the column. Test results have indicated that the critical section can be taken at d/2 from the face of the column.
Diagonal Tension Failure
Two Principal Kinds of Failure for Foundations
- Structural Failure of the Foundation - bending, shear and bearing
- Bearing Capacity Failure of the Supporting Soils - shear
3 Types of Failure of Footings
- Diagonal Tension Failure
- One-way Shear Failure
- Flexure Failure
The footing fails due to the formation of inclined cracks that intercept that bottom of the slab at a distance d from the face of the column.
One way Failure
For footings carrying columns with steel base plates, it is measured from a line halfway between the face of the column and the edge of the base plate.
Distance d