Foundation
The substructure that transfers a building’s weight into the soil — footings, piles, piers and the methods used to strengthen them.
- Caisson
A watertight chamber or large drilled shaft sunk into the ground or water and filled with concrete to form a deep foundation pier.
- Footing
The widened base of a foundation that spreads structural loads over a sufficient area of ground. Footings support walls, columns, or piers and help keep soil pressure within acceptable limits.
- Grade beam
A reinforced concrete beam at or near ground level that spans between piles, piers, or isolated footings and supports the walls above.
- Pile
A long slender column driven, bored, or cast into the ground to carry building loads through weak soil to firmer strata below.
- Plinth
The lowest square slab or block at the base of a column, pedestal, or statue; also the projecting base course of a wall where it meets the ground.
- Raft foundation
A continuous reinforced concrete slab extending under the whole building, spreading loads over the entire footprint where soil bearing capacity is low or variable.
- Underpinning
The process of strengthening or deepening the foundation of an existing building, usually by extending support down to firmer ground.