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 construction, constructi ...

, is an upright support for a structure or

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 ...

such as an

arch An arch is a curved vertical structure spanning an open space underneath it. Arches may support the load above them, or they may perform a purely decorative role. As a decorative element, the arch dates back to the 4th millennium BC, but stru ...

bridge A bridge is a structure built to Span (engineering), span a physical obstacle (such as a body of water, valley, road, or railway) without blocking the path underneath. It is constructed for the purpose of providing passage over the obstacle, whi ...

. 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 of the pier is

square In geometry, a square is a regular polygon, regular quadrilateral. It has four straight sides of equal length and four equal angles. Squares are special cases of rectangles, which have four equal angles, and of rhombuses, which have four equal si ...

, or

rectangular In Euclidean plane geometry, a rectangle is a rectilinear convex polygon or 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 ...

, but other shapes are also common. In

medieval architecture Medieval architecture was the architecture, art and science of designing and constructing buildings in the Middle Ages. The major styles of the period included pre-Romanesque, Romanesque architecture, Romanesque, and Gothic architecture, Gothic. In ...

, massive circular supports called drum piers,

cruciform A cruciform is a physical manifestation resembling a common cross or Christian cross. These include architectural shapes, biology, art, and design. Cruciform architectural plan Christian churches are commonly described as having a cruciform ...

(cross-shaped) piers, and compound piers 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 many contexts columns may also be called piers. 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 that 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 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 The Arc de Triomphe de l'Étoile, often called simply the Arc de Triomphe, is one of the most famous monuments in Paris, France, standing at the western end of the Champs-Élysées at the centre of Place Charles de Gaulle, formerly named Plac ...

, 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 to Rom ...

's original plan for

St Peter's Basilica The Papal Basilica of Saint Peter in the Vatican (), or simply St. Peter's Basilica (; ), is a church of the Italian Renaissance architecture, Italian High Renaissance located in Vatican City, an independent microstate enclaved within the cit ...

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 (6March 147518February 1564), known mononymously as Michelangelo, was an Italian sculptor, painter, architect, and poet of the High Renaissance. Born in the Republic of Florence, his work was inspir ...

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

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

References

External links