Shallow foundations (spread footings, strip footings, mat foundations), deep foundations (driven piles, drilled shafts, helical piers), matching foundation type to soil conditions and loading, and frost depth considerations.
A foundation takes every load the building above it generates and transfers it into the ground at a pressure the soil can actually support — which makes foundation selection fundamentally a soil-and-load problem before it is a structural-sizing problem. This module works through spread and strip footings, when a mat foundation becomes the better shallow-foundation choice, and the three deep-foundation options — driven piles, drilled shafts, and helical piers — including how each develops capacity and how real-time installation feedback differs between them.
By the end of this module you should be able to walk through the decision sequence that moves a project from shallow footings to a mat to a deep foundation as soil conditions and loading demand it, and explain why frost protection in cold climates combines a minimum embedment depth with drainage detailing rather than depth alone — the soil-driven design logic this program's retaining walls module extends to lateral earth pressure next.