Abutment

This article is about physical structures. For the mathematical concept, see spectral sequence. For property law, see abutter. For dental structures, see abutment (dentistry).

Diagram of a bridge abutment

Modern bridge abutments on Haikou Century Bridge

An abutment is, generally, the point where two structures or objects meet. This word comes from the verb abut, which means adjoin or having common boundary. An abutment is an engineering term that describes a structure located at the ends of a bridge, where the bridge slab adjoins the approaching roadway. This structure is basically a retaining wall designed to carry the loading conditions present in bridge structures.

Specifically, an abutment may be:

• the part of a structure that supports an arch.

• the tooth or teeth that support a fixed or removable bridge.
• the part of an implant that acts as a connection between the implant and the crown.

Architecture

In architecture an abutment is formed of "solid masonry placed to resist the lateral pressure of a vault" (Nikolaus Pevsner).

Civil engineering

An abutment supports the ends of a bridge superstructure. The intermediate supports in a multi-span bridge are known as piers.

Abutments are used for the following purposes:

• to transmit the loads from the superstructure to the foundations. Resist and transmit the following loads to the foundations: loads from the superstructure, own weight, and lateral loads such as the earth pressure, surcharge live loads, and wind loads.
• to support the end of the first or the last span.
• to retain the earth underneath and adjacent to the approach roadway, and if necessary support part of the approach slab.

There are different types of abutments including:

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 metal or polymeric reinforcement

Pile Bent abutment

Similar to Spill-through Abutment

Abutment is also a term used by civil engineers in dam construction; moving water from a large reservoir to a channel such as a spillway, there are smooth transition walls at both sides named abutments which minimize the water's energy loss.

References

• Ohio Department of Transportation
• Fixed Bridge Abutments