An introduction to arches

HRISHIRAJ SARMA | A.P.I.E.D | 2014

1

What is an Arch?
 An Arch may be defined as mechanical arrangement of wedge-shaped
blocks of stones or bricks mutually supporting each other and supported at the
end by piers or abutments.
 An arch is a structure that spans a space and supports structure and weight
below it.
 Arches appeared as early as the 2nd millennium BC in Mesopotamian brick
architecture and their systematic use started with the Ancient Romans who
were the first to apply the technique to a wide range of structures.

Function of an Arch
 The function of an Arch is to carry weight of the structure above the
opening.
 Because of their shape, the blocks support each other by mutual pressure of
their own weight.
 Hence, the structure remains in the position by the resistance from the
support.

2

Basic concept

An arch is a pure compression form. It can span a large area by resolving forces
into compressive stresses and, in turn eliminating tensile stresses. This is
sometimes referred to as arch action. As the forces in the arch are carried to the
ground, the arch will push outward at the base, called thrust. As the rise, or
height of the arch decreases, the outward thrust increases. In order to maintain
arch action and prevent the arch from collapsing, the thrust needs to be
restrained, either with internal ties, or external bracing, such as abutments.
1. Keystone
2. Voussoir
3. Extrados
4. Impost
5. Intrados
6. Rise
7. Clear span
8. Abutment

3

Type of
Arch
Materials of
Construction

Geometry
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.

Flat Arch.
Semi-circular Arch.
Segmental Arch.
Relieving Arch.
Dutch of French Arch.
Elliptical Arch.
Parabolic Arch.
Four centered Arch.
Five centered Arch.
Seven centered Arch.

11.
12.
13.
14.
15.

Tree foil Arch.
Moorish Arch.
Ogee Arch.
Multifoil Arch.
Tudor Arch.

1. Stone Arch.
Rubble Arch, Aslar Arch.
2.Brick Arch.
Rough Arch, Axed Brick Arch, Gauged
Brick Arch, Arch of Brick bonds.
3. Concrete Arch
Concrete block Arch
Monolithic Concrete Arch
R.C.C Arch
4. Wooden Arch.
5. Metal Arch.


4

Types of Arches on Geometry

Flat Arch

Semi circular Arch

French of Dutch Arch

Segmental Arch

5

Types of Arches on Geometry

Relieving Arch

Different Types of Arches

6

Types Of Arches on Geometry


7


Different Types of Arches


8



9



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Types Of Arches on Material of Construction

Rough Brick Arch


Axed Brick Arch

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Types Of Arches on Material of Construction

Rubble Arch

R.C.C Arch

AshlarArch

Metal Arch


Monolithic Concrete Arch

Wooden Arch

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Uses of Arch
 Arches with a circular form, also referred to as rounded arch,
were commonly employed by the builders of ancient history,
heavy masonry arches.
 Ancient Roman builders relied heavily on the rounded arch to
span large, open areas.
 Several rounded arches placed in-line, end-to-end, form an
arcade, such as the Roman aqueduct.

Roman aqueduct near Nimes, France

Horseshoe arches (9th century) in the
Mosque of Uqba, in Kairouan, Tunisia


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Uses of Arch

 Pointed arches were most often used by builders of Gothicstyle architecture.
 The advantage to using a pointed arch, rather than a circular
arch, is that the arch action in a pointed arch produces less thrust
at the base.
 This innovation allowed for taller and more closely spaced
openings, typical of Gothic architecture

Cathedral of St. Michael and St. Gudula
in Brussels, Belgium, with its central,
pointed arch window, typical of Gothic
architecture.


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Uses of Arch

 The parabolic arch employs the principle that when weight is
uniformly applied to an arch, the internal compression resulting
from that weight will follow a parabolic profile.
 Of any arch type, the parabolic arch produces the most thrust
at the base, but can span the largest areas.
 It is commonly used in bridge design, where long spans are
needed.


15

Uses of Arch

 Vaults are essentially "adjacent arches are assembled side by
side.“
 If vaults intersect, complex forms are produced with the
intersections.
 The forms, along with the "strongly expressed ribs at the vault
intersections, were dominant architectural features of Gothic
cathedrals."

Interior vaulted ceiling of Notre
Dame de Paris, showing the ribs at
the intersection of several arches.


16

History of Arch
 True arches, as opposed to corbel arches, were known by a
number of civilizations in the Ancient Near East, the Levant, and
Mexico, but their use was infrequent and mostly confined to
underground structures such as drains where the problem of
lateral thrust is greatly diminished.

Arch of the Near East

Arch of Levant


Mayan Corbel Arch

17

History of Arch
 A rare exception is the bronze age arched city gate of
Ashkelon (modern day Israel), dating to ca. 1850 B.C.
 An early example of a voussoir arch appears in the Greek
Rhodes Footbridge.
 In 2010, a robot discovered a long arch-roofed passageway
underneath the Pyramid of Quetzalcoatl which stands in the
ancient city of Teotihuacan north of Mexico City, dated to
around 200 AD

City gate of Ashkelon

Greek Rhodes Footbridge

Arch-roofed passageway
underneath the Pyramid
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of Quetzalcoatl

History of Arch
 The ancient Romans learned the arch from the Etruscans,
refined it and were the first builders to tap its full potential for
above ground buildings.
 Throughout the Roman empire, their engineers erected arch
structures such as bridges, aqueducts, and gates.


19

History of Arch
 They also introduced the triumphal arch as a military
monument.
 Vaults began to be used for roofing large interior spaces such
as halls and temples, a function which was also assumed by
domed structures from the 1st century BC onwards.

Arch of Constantine, Rome

Arch of Triumph in Genoa, Italy


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Examples of Arches

Gothic Arch

Muslim Arch

Roman Arch


Hindu Arch

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Why Arch is Important

 The arch is important because it is a marvelous way to structurally
support the mass of a building roof, a railway line, or an aqueduct, like
the ones the Romans built.
 Some of the arches built by Ancient Romans still stand today, and
they offer a mute testament to the effectiveness of the arch in
engineering.
 The arch is still in wide use today, and we even see big glue-lams
(wood glued to laminate it to make large beams) in the shape of arches.
The arch has a long history in structures man has built


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An introduction to arches

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