Spread Footing/Shallow Foundation Analysis and Design
U Win Aung Cho
Types of Spreading Footings
1. Single Footing Shape of single footing may be square, rectangle or circular. Trapezoidal or any other unsymmetrical shape should be avoided.
2. Combined Footing Two columns may be combined because of the area limitation of one column due to existent of property line or other structure.
3. Strip Footing Two or more columns may be combined in single direction of line for economy (continuous slab is cheaper then cantilever slab) and to reduce differential settlement between adjacent columns.
4. Grid Foundation Two orthogonal sets of strip footing are combined in two directions of lines.
5. Mat Footing All the foundation slabs are merged into one resulting mat footing. Rigidity is better and it reduces differential settlement and variation or pressure under foundation. The continuous foundation such as strip, grid and mat may be designed with or without beam and pedestals. A footing without beam is flexible and its analysis may request more accurate method such as finite element or finite difference methods.
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