Final answer:
The spread footing foundation is considered a shallow foundation type. It is used to distribute the load of a structure over a larger area to prevent sinking into the soil.
Step-by-step explanation:
When it comes to foundation types, they are generally categorized into two main groups: shallow foundations and deep foundations. The spread footing foundation falls under the category of shallow foundations. Shallow foundations are typically used where the loads imposed by a structure are relatively low relative to the bearing capacity of the surface soils.
A spread footing foundation is a common type of shallow foundation that spreads the load from a building's columns or walls over a larger area. This is to prevent the building from sinking into the soil. On the other hand, pile foundations and caisson foundations are considered deep foundations, used to transfer building loads to a deeper, more stable layer of soil when the surface is not strong enough to support the load. The raft foundation, also known as a mat foundation, is another type of shallow foundation which involves a thick concrete slab that covers a large area, often the entire footprint of the building, providing support for multiple points of contact or an entire structure.