Spread Footing/Shallow Foundation

1 Types of Spreading Footings

a. Single Footing

Shape of single footing may be square, rectangle or circular. Trapezoidal or any other unsymmetrical shape should be avoided.

b. 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

c. Combined Footing

 

Two columns may be combined because of the area limitation of one column due to existent of property line or other structure.

d. Grid Foundation

Two orthogonal sets of strip footing are combined in two directions of lines.

e. 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.