A column or pillars in architecture and structural engineering is a structural element that transmits, through compression, the weight of the above structure to other structural elements below. In other words, the column is a member of compression. The term column applies primarily to large round support ( pivot columns) with capital and base or pedestal made of stone, or looks so. The support of wood or small metal is usually called a post, and it supports with other rectangular or non-spherical parts which are usually called docks. For purposes of wind or earthquake engineering, columns may be designed to withstand lateral forces. Other compression members are often called "columns" because of similar stress conditions. Columns are often used to support beams or arches where the top of the wall or ceiling is rested. In architecture, "columns" refers to structural elements that also have certain proportional and decorative features. Columns may also be decorative elements that are not needed for structural purposes; many columns are "engaged", meaning part of the wall.
Video Column
Histori
All significant Iron Age civilizations from the Near East and the Mediterranean made some use of the columns. In the architecture of Ancient Egypt in the early 2600 BC, the architect Imhotep used a stone column whose surface was carved to reflect the organic form of a bundled reed; later on the cylinder faceted Egyptian design is also common. The famous Egyptian column is present at the Great Hypostyle Hall of Karnak (ca. 1224 BC), where 134 columns line up in 16 rows, with multiple columns reaching a height of 24 meters.
Some of the most complicated columns in the ancient world are from Persia, especially the large stone columns established at Persepolis. They include a double-bull structure in their capital city. Hundred Hall Columns in Persepolis, measuring 70 ÃÆ'â € "70 meters, was built by the Achaemenid king Darius I (524-486 BC). Many ancient Persian columns stand, some have a height of more than 30 meters.
The Minoans tribe uses a whole tree trunk, usually upside down to prevent regrowth, standing on a base located on the stylobate (floor floor) and topped with a simple round capital. It is then painted as in the most famous Minoan castle in Knossos. The Minoans use columns to create large open spaces, light-wells and as a focal point for religious rituals. These traditions are followed by later Mycenaean civilizations, especially in megarons or halls at the heart of their palaces. The importance of their columns and references to the palace and therefore authority is evidenced in its use in the heraldic motifs such as the famous lion gate of Mycenae where two lions stand on each side of the column. Because it is made of wood, these early columns can not survive, but their stone bases have been and through this we can see their use and arrangement in these palace buildings.
The Egyptians, Persians and other civilizations mostly used columns for the practical purpose of lifting the roof inside a building, preferring the outer walls to be decorated with reliefs or paintings, but the Ancient Greeks, followed by the Romans, happy to use them outside as well, and the use wide columns on the interior and exterior of the building is one of the most distinctive features of classical architecture, in buildings such as the Parthenon. The Greeks developed a classical architectural order, most easily distinguished by the shape of columns and its various elements. Their Doric, Ionic, and Corinthian orders were expanded by the Romans to include Tuscan and Composite commands (see below).
Columns, or at least a large structural exterior, become less significant in Medieval architecture. Classical forms were abandoned in Byzantine architecture and Roman and Gothic architecture in Europe to support a more flexible form, with the capital often using different kinds of ornamental foliage, and in Western scenes with relievedly carved figures. The Renaissance architecture is keen to revive the classical vocabulary and style, and the use of information and variations of the classical order remains fundamental to the training of architects throughout the Baroque, Rococo and Neo-classical architecture.
Maps Column
Structure
The earliest columns were built of stone, some of a single piece of stone. Monolithic columns are one of the toughest rocks used in architecture. Other stone columns are made of several pieces of stone, mortar or dried-up together. On many classical sites, column sections are carved with central or depressed holes so they can be broken, using stone or metal pins. The most classic column design incorporates the entasis (inclusion of slightly curves out on the sides) plus a reduction in diameter along the column height, so that the top is as little as 83% of the bottom diameter. This reduction mimics the parallax effects that the eye expects to see, and tends to make the columns look taller and more straight than they are while the entities add to that effect.
Nomenclature
Most classical columns appear from the base, or base, which is based on the stylobate, or foundation, except for the Doric order, which is usually located directly on the stylobate. The base may consist of several elements, beginning with a rectangular plate known as a base. The simplest base consists of a base only, sometimes separated from columns by circular bearing convex known as torus. The more complicated bases include two toruses, separated by a concave or channel known as scotia or trochilus. Scotiae can also occur in pairs, separated by a convex section called astragal, or bead, narrower than the torus. Sometimes this section is accompanied by a narrower convex section, known as an annulet or fillet.
At the top of the shaft is the capital, where the roof or other architectural elements rest. In the case of Doric columns, the capital usually consists of a round, oval, or echinus cushion, supporting a square plate, known as an abax or an abacus. The Ionic capital features a pair of volute, or scrolls, while the capital of Korinthian is decorated with reliefs in the form of acanthus leaves. Either type of capital can be accompanied by the same mold as the base. In the case of free-standing columns, the decorative elements above the shaft are known as finials.
Modern columns can be constructed of steel, cast or precast concrete, or bricks, left blank or clad in an architectural cover, or veneer. Used to support arches, walkers, or docks, is a member of the top column. The lower part of the arch, called the spring, rests on a clone.
Equilibrium, instability, and charge
Since the axial load on the perfectly straight slim column with the elastic material properties increases in magnitude, this ideal column passes through three conditions: stable equilibrium, neutral equilibrium, and instability. Straight columns under the load are in stable equilibrium if the lateral force, applied between the two ends of the column, results in a small lateral deflection that disappears and the column returns to a straight form when the lateral force is released. If the column load is gradually increased, a condition is reached where the straight form of equilibrium becomes what is called a neutral equilibrium, and a small lateral force will result in a deflection that is not lost and the column remains in this slightly bent form when the lateral force is removed. The load at which the neutral balance of the column is reached is called a critical load or buckling. The instability state is achieved when a slight increase in column load causes uncontrolled growth of uncontrolled lateral deflection leading to total collapse.
For straight columns loaded axially with all end supporting conditions, the static equilibrium equation, in the form of differential equations, can be solved for deflected forms and column critical loads. With the hinged, fixed or free support conditions, the deflected shape in the neutral equilibrium of the initially straight column with a uniform cross-section along its length always follows the form of partial or composite sinusoidal curves, and the critical load is given by
where E = modulus of material elasticity, I min = minimum inertia moment of cross section, and L = actual length from the column between the two ends it supports. The variant of (1) is given by
where r = the radius of the same [column] rotational rotation with the square root of (I/A), K = the ratio of the longest sine wave to the actual column length, and < i> KL = effective length (the length of the equivalent equivalent hinged column). From Equation (2) it can be noted that the buckling strength of the column is inversely proportional to the square of its length.
When stress is critical, F cr ( F cr = P cr / A , where A Ã, = column cross-sectional area), greater than the material proportional limit, the column is inelastic buckling. Because at this pressure the slope of the stress-strain curve of the material, E t (called the tangent modulus), is smaller than the proportional limit, critical on reduced inelastic buckling. More complex formulas and procedures apply to such cases, but in the simplest form the critical buckling load formula is given as Eq. (3),
di mana E t = modulus tangen pada tekanan F cr
A column with a cross section that has no symmetry may experience a previous torsional bending, or in combination with lateral buckling. The presence of twisted deformation makes theoretical analysis and practical design somewhat complex.
Eccentricity of load, or imperfections such as initial curvature, decreases column strength. If the axial load on the column is not concentric, that is, its working line does not coincide precisely with the centroidal axis of the column, the column is characterized as an eccentric load. The load eccentricity, or the initial curvature, directs the column to the immediate bending. Increased pressure due to combined axial-plus-bending stress results in the ability to carry reduced loads.
The column element is considered large if its smallest side dimension is equal to or greater than 400 mm. Large columns have the ability to increase carrier strength over long periods of time (even during heavy load periods). Taking into account the fact that the structural load may increase over time as well (and also the threat of progressive failure), large columns have advantages over non-massive ones.
Extensions
When a column is too long to be built or transported intact, the column must be extended or connected at the construction site. A reinforced concrete column is extended by having a reinforcing steel rod protruding several inches or feet above the top of the concrete, then placing the next reinforcement reinforcement level for overlap, and pouring the next level of concrete. A steel column is extended by welding or bolting the splice plate on the flanges and nets or column walls to provide a few inches or feet of load removal from the top column to the bottom. A wooden column is usually extended by using a steel tube or sheet metal plate wrapped in two wooden sections.
Foundation
The column that carries the load to the foundation must have the means to transfer the load without overly pressing the foundation material. Reinforced concrete and brick columns are generally built directly on a concrete foundation. When sitting on a concrete foundation, the steel column must have a base plate to spread the load over a larger area, thereby reducing the bearing pressure. The base plate is a thick rectangular steel plate that is usually welded to the bottom of the column.
Classical commands
The Roman writer Vitruvius, who relies on (now missing) writings from Greek writers, tells us that the ancient Greeks believed that their Doric order developed from techniques for building wood. Finer tree trunks were previously replaced with stone cylinders.
Doric Order
The Doric order is the oldest and simplest of the classic orders. It consists of a wider vertical cylinder at the bottom. It generally has no base or detailed capital. This is often topped with an upside-down frustration of a shallow cone or a group of cylindrical carvings. This is often referred to as the masculine order because it is represented at the lower levels of the Colosseum and Parthenon, and is therefore considered to withstand more weight. The height-to-bold ratio is about 8: 1. The Doric Column bar is almost always fluted.
The Greek Doric, developed in the western region of Dorian in Greece, is the heaviest and largest of the orders. It rises from stylobate without base; it is four to six times higher than its diameter; has twenty large flutes; Its capital consists only of a neck-neck that swells into a fine echinus, which carries a flat square abacus; Doroth entablature is also the toughest, about a quarter of a tall column. The Greek Doric order is not used after c. 100 B.C. until "rediscovery" in the mid-eighteenth century.
Tuscan order
The Tuscan order, also known as Roman Doric, is also a simple, basic and modal design both of which are a series of cylindrical discs with alternating diameters. The trunk is almost never fluted. Proportions vary, but are generally similar to Doric columns. The height ratio is about 7: 1 wide.
Ionic sequence
Ionic columns are much more complex than Doric or Tuscan. It usually has a base and the shaft is often fluted (has a long carved groove). The capital has a volute, an ornament shaped like a scroll, in four corners. The height-to-bold ratio is about 9: 1. Because of the finer proportions and scroll capital, Ionic columns are sometimes associated with academic buildings. Ionic style columns are used at the second level of the Colosseum.
Corinthian Order
The order of Corinth was named for the city-state of Greece at Corinth, which was connected in that period. However, according to architectural historian Vitruvius, the column was made by the sculptor Callimachus, probably an Athenian, who drew acanthus leaves growing around the votive basket. In fact, the oldest known capital of Corinth was found in Bassae, dated 427 BC. It is sometimes called the feminine order because it is at the top of the Colosseum and holds the lowest weight, and also has a thickness ratio to the leanest height. The height to width ratio is about 10: 1.
Combined order
The Composite Order draws its name from the capital which is a combination of the Ionic and Corinthian capitals. Acanthus from the Corinthian column already has a scroll-like element, so the difference is sometimes subtle. Generally Composite is similar to Corinthian in proportion and work, often at the top level of poles. The height to width ratio is about 11: 1 or 12: 1.
Solomonic
A column of Solomon, sometimes called "barley sugar," begins at a base and ends in a capital city, which may be any order, but the axis spins in a tight spiral, producing dramatic and winding effects of movement. Solomon columns developed in the ancient world, but still rare there. A famous marble set, probably of the 2nd century, was brought to St. Peter, Rome by Constantine I, and placed around a sacred shrine, and thus familiar throughout the Middle Ages, at which time they were deemed to have been removed from the Temple of Jerusalem. This style is used in bronze by Bernini for baldachin St. The spectacular Peter, was actually a siborium (which replaced the column of Constantine), and after that became very popular with Baroque and Rococo church architects, especially in Latin America, where they were used very often. , especially on a small scale, as it is easy to produce in wood by turning on the lathe (hence the popularity of styles for spindles in furniture and stairs).
The pillar pillar
The pillar of the cemetery is a monumental grave, which usually features a prominent pillar or single column, often made of stone. A number of world cultures combine the pillars into the structure of the tomb. In the Ancient Greek colony of Lycia in Anatolia, one of these buildings is located in the tomb of Xanthos. In the town of Hannassa in southern Somalia, the ruins of houses with arches and yard are also found along with other pillar graves, including rare octagonal tombs.
Gallery
See also
- Capital
- Entities
- Huabiao
- the Marian and Holy Trinity columns
- Pilaster
- Pole (disambiguation)
- Spur (architecture)
- Stanchion
References
Source of the article : Wikipedia
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