An abutment is the substructure at the ends of a bridge

span Span may refer to: Science, technology and engineering * Span (unit), the width of a human hand * Span (engineering), a section between two intermediate supports * Wingspan, the distance between the wingtips of a bird or aircraft * Sorbitan es ...

or dam supporting its

superstructure A superstructure is an upward extension of an existing structure above a baseline. This term is applied to various kinds of physical structures such as buildings, bridges, or ships. Aboard ships and large boats On water craft, the superstruct ...

. Single-span bridges have abutments at each end which provide vertical and lateral support for the span, as well as acting as retaining walls to resist lateral movement of the earthen fill of the bridge approach. Multi-span bridges require

piers Piers may refer to: * Pier, a raised structure over a body of water * Pier (architecture), an architectural support * Piers (name), a given name and surname (including lists of people with the name) * Piers baronets, two titles, in the baronetages ...

to support ends of spans unsupported by abutments. Dam abutments are generally the sides of a valley or gorge, but may be artificial in order to support arch dams such as Kurobe Dam in Japan. The civil engineering term may also refer to the structure supporting one side of an

arch An arch is a vertical curved structure that spans an elevated space and may or may not support the weight above it, or in case of a horizontal arch like an arch dam, the hydrostatic pressure against it. Arches may be synonymous with vaul ...

, or masonry used to resist the lateral forces of a vault.Pevsner, N. (1970) ''Cornwall''; 2nd ed. Harmondsworth: Penguin; p. 245 The impost or abacus of a column in classical architecture may also serve as an abutment to an arch. The word derives from the verb " abut", meaning to "touch by means of a mutual border".

Use in engineering

An abutment may be used for the following: * To transfer loads from a superstructure to its foundation elements * To resist or transfer self weight, lateral loads (such as the earth pressure) and wind loads * To support one end of an approach slab * To maintain a balance in between the vertical and horizontal force components of an arch bridge.

Types

Types of abutments include: * Gravity abutment, resists horizontal earth pressure with its own dead weight * U abutment, U-shaped gravity abutment * Cantilever abutment, cantilever retaining wall designed for large vertical loads * Full height abutment, cantilever abutment that extends from the underpass grade line to the grade line of the overpass roadway * Stub abutment, short abutments at the top of an embankment or slope, usually supported on piles * Semi-stub abutment, size between full height and stub abutment * Counterfort abutment, similar to counterfort retaining walls * Spill-through abutment, vertical buttresses with open spaces between them * MSE systems, "reinforced earth" system: modular units with metallic reinforcement * Pile bent abutment, similar to spill-through abutment

References

External links

Ohio Department of Transportation

Fixed Bridge Abutments
{{Authority control Bridges Civil engineering Dams Foundations (buildings and structures) Bridge components