In terms of foundation design, what is a caisson primarily intended for?

A caisson is primarily intended for deep load support, making it an effective choice for structures that require substantial foundation strength and stability. This type of foundation is typically used when the surface soil conditions are inadequate to support loads from a structure without significant settling or shifting.

Caissons are constructed deep into the ground, often extending below any potentially unstable layers, allowing them to rest on more solid bedrock or a stable layer of soil. This deep foundation capability is especially useful in situations where surface soil is too weak or compressible, or when there are significant loads, such as those from large buildings, bridges, or other heavy structures.

In contrast, other options do not align with the primary function of a caisson. A shallow foundation deals with structures that require less depth, soil stabilization is focused on improving the characteristics of soil rather than directly supporting loads, and drainage management pertains to controlling water flow rather than providing structural support. Therefore, the use of caissons is specifically tied to their design for deep load support, making them essential in many construction scenarios where strength and safety are critical.