These may be square, rectangular or circular in plan.
This type of footing is preferred when only single column is appearing in the foundation plan of a particular project.
Combined footing:
Combined footing supports two or more column loads.
These may be continuous with rectangular or trapezoidal in plan.
Need: - i) When the isolated footing overlaps. ii) When the exterior column is close to the property line such that isolated footing cannot be provided.