A column in structural engineering is a vertical structural element that transmits, through compression, the weight of the structure above to other structural elements below. Structural engineering is a field of Engineering dealing with the analysis and design of Structures that support or resist loads Structural engineering is Physical compression is the result of the subjection of a material to Compressive stress, resulting in reduction of Volume. Other compression members are often termed columns because of the similar stress conditions. A compression member is a general class of structural elements of which a Column is the most common specific example Columns are frequently used to support beams or arches on which the upper parts of walls or ceilings rest. An arch is a structure that spans a space while supporting weight (e In architecture "column" refers to such a structural element that also has certain proportional and decorative features. A column might not support any major structure but be a decorative or triumphant feature with e. g a statue on top.
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History
In the architecture of ancient Egypt as early as 2600 BC the architect Imhotep made use of stone columns whose surface was carved to reflect the organic form of bundled reeds; in later Egyptian architecture faceted cylinders were also common. Ancient Egypt was an Ancient Civilization in eastern North Africa, concentrated along the lower reaches of the Nile River in what is now The 26th century BC is a Century which lasted from the year 2600 BC to 2501 BC Imhotep (sometimes spelled Immutef, Im-hotep, or Ii-em-Hotep, circa ( fl
Some of the most elaborate columns in the ancient world were those of Persia especially the massive stone columns erected in Persepolis. The Persian Empire was a series of Iranian empires that ruled over the Iranian plateau, the original Persian homeland and beyond in Western Asia Persepolis ( Old Persian: Pārsa, Modern Persian: تخت جمشید/پارسه Takht-e Jamshid or Chehel Minar) was the ceremonial They included double-bull structures in their capitals. The Hall of Hundred Columns at Persepolis, measuring 70 × 70 meters was built by the Achaemenid king Darius I (524–486 BC). The Achaemenid Empire or Achaemenid Persian Empire ( haχɒmaneʃijɒn (558–330 BC was the first of the Persian Empires to rule over significant portions of Darius I the Great (c 549 BC&ndash486 BC 𐎭𐎠𐎼𐎹𐎺𐎢𐏁 Dārayavahuš: "Possessing goodness" Having ascended to power amidst controversy and bloodshed Many of the ancient Persian columns are standing, some being more than 30 meters tall.
The impost (or pier) is the topmost member of a column. The bottom-most part of the arch, called the springing, rests on the impost.
Structure
Early columns were constructed of stone, some out of a single pieces of stone, usually by turning on a lathe-like apparatus. Single-piece columns are among the heaviest stones used in architecture. Other stone columns are created out of multiple sections of stone, mortared or dry-fit together. In many classical sites, sectioned columns were carved with a center hole or depression so that they could be pegged together, using stone or metal pins. The design of most classical columns incorporates entasis (the inclusion of a slight outward curve in the sides) plus a reduction in diameter along the height of the column, so that the top is as little as 83% of the bottom diameter. In Architecture, entasis is the application of a convex curve to a surface for aesthetic purposes This reduction mimics the parallax effects which the eye expects to see, and tends to make columns look taller and straighter than they are while entasis adds to that effect.
Modern columns are constructed out of steel, poured or precast concrete, or brick. They may then be clad in an architectural covering (or veneer), or left bare.
Equilibrium, instability, and loads
As the axial load on a perfectly straight slender column with elastic material properties is increased in magnitude, this ideal column passes through three states: stable equilibrium, neutral equilibrium, and instability. The Corinthian order is one of the Classical orders of Greek and Roman Architecture, characterized The Temple of Bel is an ancient stone ruin located in Palmyra, Syria. The straight column under load is in stable equilibrium if a lateral force, applied between the two ends of the column, produces a small lateral deflection which disappears and the column returns to its straight form when the lateral force is removed. If the column load is gradually increased, a condition is reached in which the straight form of equilibrium becomes so-called neutral equilibrium, and a small lateral force will produce a deflection that does not disappear and the column remains in this slightly bent form when the lateral force is removed. The load at which neutral equilibrium of a column is reached is called the critical or buckling load. In Engineering, buckling is a failure mode characterized by a sudden failure of a structural member subjected to high Compressive stresses where The state of instability is reached when a slight increase of the column load causes uncontrollably growing lateral deflections leading to complete collapse.
For an axially loaded straight column with any end support conditions, the equation of static equilibrium, in the form of a differential equation, can be solved for the deflected shape and critical load of the column. With hinged, fixed or free end support conditions the deflected shape in neutral equilibrium of an initially straight column with uniform cross section throughout its length always follows a partial or composite sinusoidal curve shape, and the critical load is given by
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(1) |
where E = modulus of elasticity of the material, Imin = the minimal moment of inertia of the cross section, and L = actual length of the column between its two end supports. A variant of (1) is given by
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(2) |
where r = radius of gyration of [column]cross-section which is equal to the square root of (I/A), K = ratio of the longest half sine wave to the actual column length, and KL = effective length (length of an equivalent hinged-hinged column). Remote Authentication Dial In User Service ( RADIUS) is a networking protocol that provides centralized access authorization and accounting management for people or computers From Equation (2) it can be noted that the buckling strength of a column is inversely proportional to the square of its length.
When the critical stress, Fcr (Fcr =Pcr/A, where A = cross-sectional area of the column), is greater than the proportional limit of the material, the column is experiencing inelastic buckling. Since at this stress the slope of the material's stress-strain curve, Et (called the tangent modulus), is smaller than that below the proportional limit, the critical load at inelastic buckling is reduced. For the tangent function see Trigonometric functions. For other uses see Tangent (disambiguation. More complex formulas and procedures apply for such cases, but in its simplest form the critical buckling load formula is given as Equation (3),
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(3) |
where Et = tangent modulus at the stress Fcr
A column with a cross section that lacks symmetry may suffer torsional buckling (sudden twisting) before, or in combination with, lateral buckling. The presence of the twisting deformations renders both theoretical analyses and practical designs rather complex.
Eccentricity of the load, or imperfections such as initial crookedness, decreases column strength. If the axial load on the column is not concentric, that is, its line of action is not precisely coincident with the centroidal axis of the column, the column is characterized as eccentrically loaded. The eccentricity of the load, or an initial curvature, subjects the column to immediate bending. The increased stresses due to the combined axial-plus-flexural stresses result in a reduced load-carrying ability.
Extensions
When a column is too long to be built or transported in one piece, it has to be extended or spliced at the construction site. A reinforced concrete column is extended by having the steel reinforcing bars protrude a few inches or feet above the top of the concrete, then placing the next level of reinforcing bars to overlap, and pouring the concrete of the next level. A steel column is extended by welding or bolting splice plates on the flanges and webs or walls of the columns to provide a few inches or feet of load transfer from the upper to the lower column section. A timber column is usually extended by the use of a steel tube or wrapped-around sheet-metal plate bolted onto the two connecting timber sections.
Foundations
A column that carries the load down to a foundation must have means to transfer the load without overstressing the foundation material. Reinforced concrete and masonry columns are generally built directly on top of concrete foundations. A steel column, when seated on a concrete foundation, must have a base plate to spread the load over a larger area and thereby reduce the bearing pressure. The base plate is a thick rectangular steel plate usually welded to the bottom end of the column.
Classical orders
The Roman author Vitruvius, relying on the writings (now lost) of Greek authors, tells us that the ancient Greeks believed that their Doric order developed from techniques for building in wood in which the earlier smoothed tree trunk was replaced by a stone cylinder. A classical order is one of the ancient styles of building design in the classical tradition, distinguished by their proportions and their characteristic profiles and details San Prospero is a Comune (municipality in the Province of Modena in the Italian region Emilia-Romagna, located about 40 km northwest For the city in the southern Italy See Reggio Calabria. For the basketball club "Bipop Carire Reggio Emilia" see Pallacanestro Reggiana. Italy (Italia officially the Italian Republic, (Repubblica Italiana is located on the Italian Peninsula in Southern Europe, and on the two largest Ancient Rome was a Civilization that grew out of a small agricultural community founded on the Italian Peninsula as early as the 10th century BC Marcus Vitruvius Pollio (born c 80–70 BC died after c 15 BC was a Roman Writer, Architect and Engineer (possibly praefectus fabrum The term ancient Greece refers to the period of Greek history lasting from the Greek Dark Ages ca The term ancient Greece refers to the period of Greek history lasting from the Greek Dark Ages ca
Doric order
The Doric order is the oldest and simplest of the classical orders. The Doric order was one of the three '''orders''' or organizational systems of Ancient Greek or Classical architecture; the other two Canonical The Doric order was one of the three '''orders''' or organizational systems of Ancient Greek or Classical architecture; the other two Canonical It is composed of a vertical cylinder that is wider at the bottom. A cylinder is one of the most basic curvilinear geometric shapes the Surface formed by the points at a fixed distance from a given Straight line, the axis It generally has neither a base nor a detailed capital. In several traditions of Architecture including Classical architecture, the capital (from the Latin caput 'head' forms the crowning member It is instead often topped with an inverted frustum of a shallow cone or a cylindrical band of carvings. Elements special cases and related concepts Each plane section is a base of the frustum It is often referred to as the masculine order because it is represented in the bottom level of the Colosseum and the Parthenon, and was therefore considered to be able to hold more weight. The Colosseum or Roman Coliseum, originally the Flavian Amphitheatre ( Latin: Amphitheatrum Flavium, Italian Anfiteatro Flavio The Parthenon ( Ancient Greek:) is a temple of the Greek goddess Athena, built in the 5th century BC on the Athenian Acropolis The height-to-thickness ratio is about 8:1. The shaft of a Doric Column is almost always fluted.
Tuscan order
The Tuscan order, also known as Roman Doric, is also a simple design, the base and capital both being series of cylindrical disks of alternating diameter. Among the Classical orders of Architecture, the Tuscan order's place in the architectural canon is disputed Among the Classical orders of Architecture, the Tuscan order's place in the architectural canon is disputed The shaft is almost never fluted. The proportions vary, but are generally similar to Doric columns. Height to width ratio is about 7:1.
Ionic order
The Ionic column is considerably more complex than the Doric or Tuscan. The Ionic order column forms one of the three '''orders''' or '''organizational systems''' of Classical architecture, the other two canonic orders being the The Ionic order column forms one of the three '''orders''' or '''organizational systems''' of Classical architecture, the other two canonic orders being the It usually has a base and the shaft is often fluted (it has grooves carved up its length). On the top is a capital in the characteristic shape of a scroll, called a volute, or scroll, at the four corners. A scroll is a roll of Papyrus, Parchment, or Paper which has been written drawn or painted upon for the purpose of transmitting information or using as A volute is a spiral scroll-like ornament that forms the basis of the Ionic order, found in the capital of the Ionic column The height-to-thickness ratio is around 9:1. Due to the more refined proportions and scroll capitals, the Ionic column is sometimes associated with academic buildings.
Corinthian order
The Corinthian order is named for the Greek city-state of Corinth, to which it was connected in the period. The Corinthian order is one of the Classical orders of Greek and Roman Architecture, characterized The Corinthian order is one of the Classical orders of Greek and Roman Architecture, characterized A city-state is a Region controlled exclusively by a City, usually having Sovereignty. Corinth, or Korinth ( Greek Κόρινθος ( is a city in Greece. However, according to the Greek architectural historian Vitruvius, the column was created by the sculptor Callimachus, probably an Athenian, who drew acanthus leaves growing around a votive basket. For the Alexandrian poet and keeper of the Museum see Callimachus of Cyrene. Athens (ˈæθənz Αθήνα Athina,) the Capital and largest city of Greece, dominates the Attica periphery as one of the world's Acanthus is a Genus of about 30 species of Flowering plants in the family Acanthaceae, native to tropical and warm temperate regions of the In fact, the oldest known Corinthian capital was found in Bassae, dated at 427 BC. Events By place Greece Sparta 's King Archidamus II is succeeded by his son Agis II. It is sometimes called the feminine order because it is on the top level of the Colosseum and holding up the least weight, and also has the slenderest ratio of thickness to height. Height to width ratio is about 10:1.
Composite order
The Composite order draws its name from the capital being a composite of the Ionic and Corinthian capitals. The composite order is a mixed order, combining the Volutes of the Ionic order with the leaves of the Corinthian order. The acanthus of the Corinthian column already has a scroll-like element, so the distinction is sometimes subtle. Generally the Composite is similar to the Corinthian in proportion and employment, often in the upper tiers of colonnades. Height to width ratio is about 11:1 or 12:1.
Solomonic
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Solomonic columns were inventions of Baroque architects in Europe. The Solomonic column, also called Barley-sugar column, is a helical Column, characterized by a spiraling twisting shaft like a corkscrew Baroque art redirects here Please disambiguate such links to Baroque painting, Baroque sculpture, etc They were not used in antiquity, but were called “Solomonic” by baroque architects because they were based on a description of columns in the great temple of King Solomon in the Old Testament. A temple (from the Latin word Templum) is a structure reserved for religious or spiritual activities such as prayer and sacrifice or analogous rites King Solomon ( Ge'ez: ስለሞን Arabic: ar سليمان, Sulayman, all from the Triliteral root S-L-M, "peace" In Western Christianity, the Old Testament refers to the books that form the first of the two-part Christian Biblical canon. A Solomonic column begins on a base and ends in a capital, just like a classical column, but the shaft twists around the usual parameters of a column, producing a dramatic, serpentine effect of movement. The most famous use of Solomonic columns is in the baldocchino designed by Bernini for Saint Peter’s Basilica in the Vatican City. "Bernini" redirects here For people named Bernini see Bernini (surname. The Basilica of Saint Peter (Basilica Sancti Petri officially known in Italian as the Basilica di San Pietro in Vaticano and commonly known as St Vatican City, officially the State of the Vatican City (Stato della Città del Vaticano is a Landlocked sovereign City-state whose territory
Notable columns
- Alexander Column
- Ashoka Column
- Berlin victory column
- Holy Trinity Column in Olomouc
- Iron Column
- Monument to the Great Fire of London
- Nelson's Column
- Rostral Columns
- Sigismund's Column
- Trajan's Column
See also
- Pier (architecture)
- Colonnade
- Persian column
- Pilaster
- Buckling
- Spur (architecture)
- Marian and Holy Trinity columns
- Doric Order
- Tuscan Order
- Ionic Order
- Corinthian Order
- Composite Order
- Entasis
- Stanchion
Dictionary
column
-noun
- An upright supporting member.
- A vertical line of entries in a table, going from top to bottom; as opposed to a horizontal row (going from left to right).
- A body of troops or army vehicles, usually strung out along a road.
- A vertical body of text in a newspaper or other journal.
- Anything having similar vertical form or structure to the things mentioned above, such as a spinal column, etc.
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