What are relevant design considerations?
The relevant design considerations may be summarized as follows:
a. Main reinforcement (uniformly distributed) is placed in a longitudinal direction assuming that the footing is a longitudinal beam.
b. Shear should be checked for both one way shear and two way shears for the columns.
c. Stirrups or bent bars may be needed to maintain an economical footing thickness. This assumes that the shear effect is uniform across the width of the footing.
d. Transverse reinforcement is uniformly placed at the bottom of the footing within a band having a width not greater than the column width plus twice the effective depth of the footing. The design procedure is similar to that of individual column footings.
e. Longitudinal steel is also placed at the bottom of the footing in order to tie together and position the stirrups and transverse steel. Although the required steel area may be small, the effect of cantilever moments in the vicinity of columns should be checked.