A pier, in

architecture Architecture is the art and technique of designing and building, as distinguished from the skills associated with construction. It is both the process and the product of sketching, conceiving, planning, designing, and constructing building ...

, is an upright support for a structure or superstructure such as 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 ...

bridge A bridge is a structure built to span a physical obstacle (such as a body of water, valley, road, or rail) without blocking the way underneath. It is constructed for the purpose of providing passage over the obstacle, which is usually somethi ...

. Sections of structural walls between openings (bays) can function as piers. External or free-standing walls may have piers at the ends or on corners.

Description

The simplest

cross section Cross section may refer to: * Cross section (geometry) ** Cross-sectional views in architecture & engineering 3D *Cross section (geology) * Cross section (electronics) * Radar cross section, measure of detectability * Cross section (physics) **Abs ...

of the pier is

square In Euclidean geometry, a square is a regular quadrilateral, which means that it has four equal sides and four equal angles (90- degree angles, π/2 radian angles, or right angles). It can also be defined as a rectangle with two equal-length a ...

, or

rectangular In Euclidean plane geometry, a rectangle is a quadrilateral with four right angles. It can also be defined as: an equiangular quadrilateral, since equiangular means that all of its angles are equal (360°/4 = 90°); or a parallelogram containin ...

, but other shapes are also common. In

medieval architecture Medieval architecture is architecture common in the Middle Ages, and includes religious, civil, and military buildings. Styles include pre-Romanesque, Romanesque, and Gothic. While most of the surviving medieval architecture is to be seen in c ...

, massive

circular Circular may refer to: * The shape of a circle * ''Circular'' (album), a 2006 album by Spanish singer Vega * Circular letter (disambiguation) ** Flyer (pamphlet), a form of advertisement * Circular reasoning, a type of logical fallacy * Circular ...

supports called drum piers,

cruciform Cruciform is a term for physical manifestations resembling a common cross or Christian cross. The label can be extended to architectural shapes, biology, art, and design. Cruciform architectural plan Christian churches are commonly described ...

(cross-shaped) piers, and

compound pier Compound pier or cluster pier is the architectural term given to a clustered column or pier which consists of a centre mass or newel, to which engaged or semi-detached shafts have been attached, in order to perform (or to suggest the performance ...

s are common architectural elements.

Column A column or pillar in architecture and structural engineering is a structural element that transmits, through compression, the weight of the structure above to other structural elements below. In other words, a column is a compression member. ...

s are a similar upright support, but stand on a round base. In buildings with a sequence of bays between piers, each opening (window or door) between two piers is considered a single bay.

Bridge piers

Poinciana Parkway RCMB bridge construction 4

Single-span

s have

abutment An abutment is the substructure at the ends of a bridge span or dam supporting its superstructure. Single-span bridges have abutments at each end which provide vertical and lateral support for the span, as well as acting as retaining walls ...

s at each end that support the weight of the bridge and serve as retaining walls to resist lateral movement of the earthen fill of the bridge approach. Multi-span bridges require piers to support the ends of spans between these abutments. In cold climates, the upstream edge of a pier may include a

starkwater In architecture, a starling (or sterling) is a defensive bulwark, usually built with pilings or bricks, surrounding the supports (or piers) of a bridge or similar construction. Starlings may be shaped to ease the flow of the water around the brid ...

to prevent accumulation of broken ice during peak snowmelt flows. The starkwater has a sharpened upstream edge sometimes called a ''cutwater''. The cutwater edge may be of concrete or masonry, but is often capped with a steel angle to resist abrasion and focus force at a single point to fracture floating pieces of ice striking the pier. In cold climates, the starling is typically sloped at an angle of about 45° so current pushing against the ice tends to lift the downstream edge of the ice translating horizontal force of the current to vertical force against a thinner cross-section of ice until unsupported weight of ice fractures the piece of ice allowing it to pass on either side of the pier.

Examples

In the Arc de Triomphe, Paris (''illustration, right'') the central arch and side arches are raised on four massive .

St Peter's Basilica

Donato Bramante Donato Bramante ( , , ; 1444 – 11 April 1514), born as Donato di Pascuccio d'Antonio and also known as Bramante Lazzari, was an Italian architect and painter. He introduced Renaissance architecture to Milan and the High Renaissance style ...

's original plan for

St Peter's Basilica The Papal Basilica of Saint Peter in the Vatican ( it, Basilica Papale di San Pietro in Vaticano), or simply Saint Peter's Basilica ( la, Basilica Sancti Petri), is a church built in the Renaissance style located in Vatican City, the papal en ...

in Rome has richly articulated piers. Four piers support the weight of the

dome A dome () is an architectural element similar to the hollow upper half of a sphere. There is significant overlap with the term cupola, which may also refer to a dome or a structure on top of a dome. The precise definition of a dome has been a m ...

at the central crossing. These piers were found to be too small to support the weight and were changed later by

Michelangelo Michelangelo di Lodovico Buonarroti Simoni (; 6 March 1475 – 18 February 1564), known as Michelangelo (), was an Italian sculptor, painter, architect, and poet of the High Renaissance. Born in the Republic of Florence, his work was insp ...

to account for the massive weight of the dome.M. Fazio, ''Buildings Across Time'', 312 The piers of the four

apse In architecture, an apse (plural apses; from Latin 'arch, vault' from Ancient Greek 'arch'; sometimes written apsis, plural apsides) is a semicircular recess covered with a hemispherical vault or semi-dome, also known as an ''exedra''. In ...

s that project from each outer wall are also strong, to withstand the outward thrust of the half-domes upon them. Many

niche Niche may refer to: Science *Developmental niche, a concept for understanding the cultural context of child development *Ecological niche, a term describing the relational position of an organism's species *Niche differentiation, in ecology, the ...

s articulate the wall-spaces of the piers. MontacuteNineWorthies

References

External links