Which type of footing is designed specifically to support a single column?

The type of footing that is specifically designed to support a single column is known as a spread footing. This type of foundation typically consists of a wide base that extends beneath the column, distributing the load over a larger area of soil to prevent excessive settlement or failure. By increasing the area of contact with the ground, spread footings help to ensure stability and support for the column.

Spread footings are particularly effective in bearing loads from structures that are concentrated at single points, as they provide the necessary support without the need for additional extends like those found in continuous or combined footings. Continuous footings, on the other hand, are used to support walls and are continuous along the length of the wall rather than at individual columns. Combined footings are utilized to support two or more columns, usually when they are close together and the soil bearing capacity is a concern. Cantilever footings serve to support loads in a manner similar to a cantilevered beam, which is not the specific application for a single column support.

Thus, the characteristics and design purpose of a spread footing align perfectly with the requirement of supporting a single column efficiently.