Which footing is primarily used in a situation involving closely spaced columns?

• A. Isolated footing
• B. Pad footing
• C. Strip footing
• D. Mat footing

Answer: (C)

In scenarios involving closely spaced columns, the most suitable choice for the footing is strip footing. This type of footing runs continuously along the length of the columns and provides support for multiple columns at once. It is designed to distribute the load from the columns over a larger area of soil, helping prevent excessive settlement.

Strip footing is particularly effective in situations where columns are aligned in a row or are very near to each other, as it eliminates the need for separate foundations for each column, thus optimizing material use and construction time. It also provides continuous support which is beneficial for load distribution, and is often easier to construct in constricted spaces than other options.

In contrast, isolated footings are typically used for single columns and are not ideal for closely spaced columns, as each would require its own footing. Pad footings function similarly to isolated footings, supporting individual columns but are usually broader and can occasionally support more than one column in certain configurations. Mat footings, while useful for closely spaced columns under heavy loads, are more extensive and are generally employed when a larger, continuous foundation is necessary to spread the loads from many columns across a wide area.