Types of Foundation (Footings )…. Best information

Foundation


Footings are structural members used to support columns and walls and to transmit and distribute their loads to the soil in such a way that the load bearing capacity of the soil is not exceeded, excessive settlement, differential settlement,or rotation are prevented and adequate safety against overturning or sliding is maintained.

Types of Foundation
1.Shallows Foundations
2.Deep Foundations
1- Shallows Foundations
Shallow foundations are those founded near to the finished ground surface; generally where the founding depth (Df) is less than the width of the footing and less than 3m. These are not strict rules, but merely guidelines: basically, if surface loading or other surface conditions will affect the bearing capacity of a foundation it is 'shallow'
Shallows foundations are used when surface soils are sufficiently strong and stiff to support the imposed loads; they are generally unsuitable in weak or highly compressible soils, such as poorly-compacted fill, peat, recent lacustrine and alluvial deposits, etc.
Shallow Foundation Types
1. Pad or column footings ( Isolated or Combined )
A-Isolated
used to support single columns. This is one of the most economical types of footings and is used when columns are spaced at relatively long distances
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B-Combined
usually support two columns, or three columns not in a row. Combined footings are used when tow columns are so close that single footings cannot be used or when one column is located at or near a property
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2. Cantilever or strap footings
consist of two single footings connected with a beam or a strap and support two single columns. This type replaces a combined footing and is more economical.
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3. Continuous footings
support a row of three or more columns. They have limited width and continue under all columns.