1. SHEET NO.
AVD CONSTRUCTION TECHNIQUES5
Arch and Vault, a fundamental construction system in
architecture used to span the space between walls, piers, or
other supports and to create a roof or a ceiling.
Until the 19th century the arch and vault were the only
alternative to the far more limited and simpler post-and-lintel
system supporting a flat or peaked beamed roof.
Brief history -
The use of arch, vault and cupola building systems in construction can be
traced back to most ancient times.
As early as the 3rd millennium BC, they were very widely used in the
countries of the Middle East and Egypt.
Arches, vaults and cupolas were also fairly widely used by Roman,
Sassanid and Byzantine builders before being adopted in many regions of
Europe.
Very many applications also emerged in North Africa, the Sudan Sahel
belt of Africa, as well as in the northern regions of China. Many of these
countries still boast a rich heritage of this kind of building, both in urban
and in rural areas. In many cases, building them is still a living tradition,
well suited to modern popular housing needs.
Diversity
The numerous types of arches, vaults and cupolas allow a great variety of
architectural models. As a result, the technology can adapt to the most
varied climatic conditions: zones which are arid or rainy, cold or hot.
Although arches, vaults and cupolas are traditionally used to cover
limited spaces, they are perfectly well suited to build much larger spaces,
up to tens of meters. Thus they can meet the needs of any building
programme, public or private, low cost or quality housing, granaries,
warehouses, shops, schools, public, religious buildings, etc.
Recent projects
Forgotten by the formal building sector since the appearance of concrete,
arches, vaults and cupolas were rediscovered in the 40's by the Egyptian
architect, Hassan Fathy, who found inspiration in the popular Nubian
tradition for the design and construction of the village of New Gourna.
ARCH
An arch, in construction, is a rigid span curving upward between
two points of support. It appears in a variety of structures, such
as an arcade, formed by a row of arches, supported by
load-bearing arches or a roof or a bridge, or as a single,
freestanding triumphal or memorial arch. The traditional stone or
brick arch, formed of many segments held in place by lateral
thrust, was developed to connect a greater distance between two
supports than a single horizontal beam, or lintel, could bridge.
Since the 19th century, arches have also been made of single,
curved spans of iron, steel, or reinforced concrete.
The masonry arch has many elements. Its supports may be walls,
piers, or columns, and the capstones from which it springs are
known as imposts. The upper part of the arch is the crown, the
portions near the impost are the haunches, its wedge-shaped
segments are voussoirs, and the central or crowning voussoir is
the keystone. The inner edge of the arch is the intrados; the outer
edge, the extrados; and the undersurface, the soffit. The molded
band that often is found around the opening of the arch is the
archivolt. The wall spaces on either side of an arch, or between
adjacent arches, are spandrels. If the space between the arch and
the lintel is filled in, the resulting flat surface is the tympanum.
Arches have been built since prehistoric times. Rude prototypes
were made by leaning two slabs of rock together or by
constructing a stepped, or corbeled, arch in which projecting
elements from a wall rise in steps from the supports to meet in
the center. The Egyptians, Babylonians, and Greeks used the arch,
generally for secular structures, such as storerooms and sewers.
The Assyrians built palaces with arched ceilings, and the Etruscans
used arches in bridges, passageways, and gates. The Romans,
however, were the first to develop the arch on a massive scale.
They used the semicircular arch freely in secular structures such
as amphitheaters, palaces, and aqueducts, but their temples
usually had the post-and-lintel construction of Greek temples. The
few vaulted exceptions, however, include the Pantheon in Rome.
During the Middle Ages, Byzantine architecture in the East and
Romanesque architecture in the West retained the characteristic
round Roman arch. Islamic architects developed a rich variety of
pointed, scalloped, horseshoe, and ogee (S-curve) arches for
mosques and palaces. In Moorish Spain, horseshoe arches were
set on delicate columns, giving a characteristic airy effect. Gothic
architecture in Western Europe was characterized by the pointed
arch, which minimized outward thrust and thus made possible
higher, thinner, window-filled walls, creating the lofty, spacious
interiors of Gothic cathedrals. In the 20th century, arches of
molded reinforced concrete based on the curve of a parabola have
been used in all sorts of public structures.
A vault, in architecture, is an arch-shaped structure, usually of
masonry, used as the ceiling of a room or other enclosed space,
as the roof of a building, or as the support for a ceiling or roof.
Masonry vaults are usually composed of wedge-shaped pieces
called voussoirs, which are held in place, like the stones of an
arch, by the pressure of the neighboring pieces. Because of the
combined pressure of its components, any arch exerts an outward
pressure at its base, and the base, therefore, must be so
constructed as to withstand the outward as well as the downward
thrust of the arch. This construction can be accomplished by using
strong, heavy walls to support the arch or by supporting the walls
with exterior structures, or buttresses. A temporary supporting
structure must be erected within the vaulted area during
construction, because a masonry vault does not become
self-supporting until the central voussoirs or keystones are put in
place.
A number of different types of vaults are used architecturally. The
simplest of these is the barrel, or tunnel, vault, the roof of which
is shaped like half a cylinder and is supported by straight walls.
The annular vault is similar to the barrel vault, except that the
passage within it is not straight but curved, giving the entire
structure the appearance of a portion of a ring. A groined vault is
formed by the intersection of two vaults of the barrel type, usually
at right angles to each other. The junctures at which the two
vaults meet are elliptical ridges, called groins. In the simplest
form of groined vault, the two conjoined vaults are of the same
size and the floor of the vault is square; if the vaults are of
different sizes, however, the floor of the vault is rectangular and
the two areas of the ceiling between the groins are of unequal
shape and size.
Project of the architect Hassan Fathy, villa at Fayoum, Egypt, 1984
DOMES
Domes are obtained by rotating an arch, except for faceted domes
which more closely resemble the dominical vault. A dome can be
semi-circular, segmental, ogival, conical, etc. domes are circular
in plan. They can, however, be used to cover square or
rectangular rooms by using pendentives or squinches. Domes on
pendentives can be used to cover any kind of polygonal shape in
plan. It is possible to combine several domes or to combine
domes with vaults.
A dome is a spherical vault resting on a circular base wall.
Pendentives are portions of spherical vaults, or spherical triangles,
placed in the corners of square or other polygonal structures to
form a circular base for a dome above. More complicated vaults
include ribbed vaults, in which the inner vault surface is
subdivided by a number of independent supporting arches, or ribs.
A further refinement is the fan vault, most common in English late
Gothic structures, in which the ribs are multiplied and grouped in
the shape of an open fan.
A VAULT
ADVANTAGES OF ARCHES, VAULTS AND CUPOLAS
The materials used for the construction of arches, vaults and cupolas can be the same as those used for walls and can be found or
produced locally.
There is no use of wood, which also totally eliminates the risks of fire. The massive nature of these structures provides good heats to
rage capacity and delay in heat transmission, meeting comfort requirements, especially in dry climate regions. This mass also gives
good sound insulation.
SUITABILITY
Arches, vaults and cupolas can often provide a good solution for covering all kinds of buildings of all sizes.
However, their acceptability and suitability to genuine needs and local climatic conditions cannot always be taken for granted.
To ensure that structures are well designed and well built, specialized training must be given at all levels: design, engineering and
construction.
Preliminary surveys are required.
LIMITATIONS OF USE
Some local conditions can limit the benefits of building with arches, vaults and cupolas: rejection by the inhabitants for cultural
reasons, high cost of labor, high cost of suitable building materials, and use in earthquake areas requires special care, lack of
building norms.
The technology must be adjusted to a given context and the techniques must be mastered, to warrant the advantages of using
arches, vaults and cupolas.
SEM
SCALE
DATE 10 - 03 - 2018
1:500
COLLEGE
SUBJECT
CLASS
R.NO.
613 - LOW COST BUILDING MATERIALS AND CONSTRUCTION TECHNIQUES.
SOUMITRA SMARTNAME
JAWAHARLAL NEHRU ENGINEERING COLLEGE, CIDCO, AURANGABAD.
20213220171703210006
M-ARCH - GENERAL
2nd
SEMESTER
