The correct answer is: A. Footing
A footing is a structural element that transfers the load of a structure to the ground. It is usually made of concrete or masonry, and it is designed to spread the load over a large area so that the pressure on the ground is not too high.
There are many different types of footings, but the most common type for a number of columns constructed in a rcjw is a spread footing. A spread footing is a rectangular or square slab of concrete that is placed under each column. The size and depth of the footing are determined by the load of the column, the type of soil, and the frost depth.
Spread footings are a simple and effective way to support a number of columns. They are relatively inexpensive to construct, and they can be used in a variety of soil conditions.
The other options are not correct because:
- A raft foundation is a large, flat slab of concrete that supports the entire structure. It is used in areas with soft or unstable soil.
- A strap foundation is a narrow strip of concrete that is used to support a single column. It is used in areas with firm soil.
- A strip foundation is a continuous strip of concrete that is used to support a row of columns. It is used in areas with firm soil.