Types of Footings and Foundation Systems
Cellular Mat
A composite structure if reinforced concrete slabs and basement walls serving as a mat foundation
Spread Footing
A concrete footing extended laterally to distribute the foundation load over a wide enough area that the allowable bearing capacity of supporting soil is not exceeded
Wall footing
A continuous type of footing intended to support as well as transmit the load imposed by the wall directly to the ground
Rectangular Footing
A footing, rectangular in plan and supporting a load of unequal magnitudes in both axis
Pile Cap
A footing-like member which joins the heads of a cluster of piles in order to distribute the load from a column or grade beam equally among the piles
Deep Foundation
A foundation system type employed when the soil underlying a foundation is unstable to transfer building loads to a mote appropriate bearing stratum
Shallow Foundation
A foundation system type which is employed when stable soil of adequate bearing capacity occurs relatively near to the ground surface
Grillage/Grid Foundation
A framework of crossing beams for spreading heavy loads over large areas
Ribbed Mat
A mat foundation reinforced by a grid of ribs above or below the slab
Raft foundation
A mat providing a footing on yielding soil
Strap/Cantilever/Connected Footing
A reinforced concrete footing connected by a tie beam to another footing in order to balance an asymmetrically imposed load, as at the perimeter of a building site
Continuous Footing
A reinforced concrete footing extended to support a tow of columns
Combined Footing
A reinforced concrete footing for a perimeter column or foundation wall extended to support an interior column load
Isolated Footing
A single spread footing supporting a freestanding column or pier
Pile Foundation
A system of piles, pile caps and tie beams for transferring building loads down to a suitable bearing stratum
Mat Foundation
A thick, slab-like heavily reinforced concrete footing supporting a number of columns or an entire building
Footing Tie Beam
A type of beam-like footing placed underneath the ground in order to transmit and provide additional rigidity to two or more columns
Stepped footing
A type of footing that changes levels in stages o accommodate a sloping grade and maintain the required depth at all points around a building with the center having the thickest part of the footing
Pile Foundation
A type of foundation system used when foundation bed is too weak to support the raft or mat or any other type of footing
Square sloped footing
A type of isolated footing having an inclined top, sloping towards the edges
Precast socket foundation
A type of precast footing provided with a socket to receive a precast column
Regular Combined Footing
Column loads on this type are assumed to be of the same magnitude
Trapezoidal Combined Footing
Column loads on this type are assumed to be of unequal magnitude
Floating Foundation
Foundation used in yielding soil
Grade Beam
Reinforced concrete beam supporting a bearing wall at or near the ground level and transferring the load to isolated footings, piers or piles
Soil/Contact Pressure
The actual pressure developed between the footing and the supporting soil mass, equal to the quotient of the magnitude of the forces and the area of contact
Strip Footing
The continuous spread footing of a foundation wall
Consolidation
The gradual reduction in the volume of a soil mass resulting from the application of a sustained load and an increase in compressive stress
Settlement
The gradual subsiding of the structure as the soil beneath its foundation consolidates under loading
Active Soil Pressure
The horizontal component of pressure that a soil mass exerts on a vertical retaining wall
Passive Soil Pressure
The horizontal component of resistance developed by a soil mass against the horizontal movement of a vertical structure through the soil
Differential Settlement
The relative movement of parts of a structure caused by uneven settlement underlying soil or failure of its foundation
