Types of Arches

Arch,Terminology,Classification

1. TYPE OF ARCHES
Ankit Shukla
ACA,Agra

2. ARCH
What is an Arch?
An Arch is a structure constructed of
wedge-shaped unit.
It spans an opening to support the
weight of the wall and other
superimpose load.
B.C.Punmia
Google.com
Reference-

3. Terminology
1.Intrados:-This is an inner curve
of an arch.
2.Extrados:-Outer Curve of an
arch
3.Soffit:-Inner Surface of an arch.
4.Voussoirs:-These are wedge
shaped units.
5.Crown:-Highest part of extrados
B.C.Punmia
W.C.MacKay
Reference-

4. 6.Spandril:-Curved triangular
space form between extrados and
horizontal line.
7.Key:-Wedge-shaped unit fixed
at the crown of the arch.
8.Skew back:-It is inclined or
splayed surface on the abutment.
9.Springing points:-These
are the points from which the
curve of the arch spring.
10.Springing line:-It is an
imaginary line joining the
springing point of either ends.
Reference-B.C.Punmia
W.C.MacKay

5. 11.Abutment:-End point of
an Arch.
12.Springer:-It is the first
voussoir at springing level.
13.Pier:-Intermediate support
of an archade.
14.Arcade:-It is a row of
arches in continuation.
15.Haunch:-Lower half of the
arch between the crown and
skew back.
Reference-B.C.Punmia
W.C.MacKay

6. 16.Ring:-It is the circular course
forming an arch.
17.Impost:-It is the projecting
course at upper part of pier or
abutment to stress the springing
line.
18.Bed Joint:-Joints between the
Voussoirs which radiate from
centre.
19.Centre or Stricking
Point:-This is geometrical
centre point from where the arc
forming the extrados, arc rings,
intrados.
20.Span:-Clear horizontal distance
between the supports.
Reference-B.C.Punmia
W.C.MacKay

7. Arches are classified according to:-
1.Shape
2.Number of Centers
3.Workmanship and Material Used
Reference-B.C.Punmia
Google.com

8. Classification According to Shape
Flat Arch
Segmental Arch
Semi-circular Arch
Pointed Arch
Florentine Arch
Stilted Arch
Horse Shoe Arch
Venetian Arch
Relieving Arch
Semi-Elliptical Arch
Reference-B.C.Punmia
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9. Flat Arch
Forms an equilateral triangle with intrados as base( at an angle of 60°)
Used only for light loads
Weakest Arch
Reference-B.C.Punmia
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10. Segmental Arch
Center of Arch lies below springing line.
Thrust transferred to the abutment is in inclined direction.
Most Common type of Arch.
Reference-B.C.Punmia
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11. Semi-circular Arch
Center Lie on Springing line
Shape of the arch is Semi-circular
Thrust transferred to the abutment is perfectly in vertical direction
Reference-B.C.Punmia
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12. Horse Shoe Arch
The arch has the shape of a horse shoe.
Incorporating more than a semi circle.
Mainly use for Architectural consideration.
Reference-B.C.Punmia
Google.com

13. Pointed Arch
Also known as Gothic Arch.
It consist two arc of the circle meeting at apex.
Triangle form may be equilateral or isosceles(also known as Lancet
Arch).
Reference-B.C.Punmia
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14. Venetian Arch
This is another form of Pointed Arch.
Has deeper depth at crown than springings.
It Has four centers located on springing line.
Reference-B.C.Punmia
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15. Florentine Arch
This is similar to Venetian Arch.
Its intrados is a semicircle.
It has three centers located on springing line.
Reference-B.C.Punmia
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16. Relieving Arch
The ends of Arch carried sufficiently into abutment.
Its lintel can be replaced without effecting the Arch.
The Arch is constructed on either flat arch or wooden lintel.
Reference-B.C.Punmia
Google.com

17. Stilted Arch
Anarchwhosecurvebeginsabovetheimpostline.
It consists a semi circular arch with two vertical portions at springings.
The centre of the arch lies on the horizontal line.
Reference-B.C.Punmia
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18. Semi-Elliptical Arch
It has shape of semi-ellipse.
It has either three centre or five centre.
Alsocalledabasket-handlearch.
Reference-B.C.Punmia
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19. Classification According to Number Of
Centers
One-Centered Arch
Two-Centered Arch
Three-Centered Arch
Four-Centered Arch
Five-Centered Arch
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20. One-Centered Arch
It has only one center.
Segmental Arches, Semicircular Arches, Flat Arches, Horse Shoe
Arches and Stilted Arches come under this Category.
Sometimes full circular arch (Bulleye Arch ) provided for circular
windows.
Reference-B.C.Punmia
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21. Two-Centered Arch
It has two centers.
Pointed Arches comes under this category.
Semi-elliptical arch and Florentine arch also comes under this category.
Reference-B.C.Punmia
Google.com

22. Three-Centered Arch
It has three centers.
Elliptical Arches comes under this category.
Equilateral Arches also comes under this category.
Reference-B.C.Punmia
Google.com

23. Four-Centered Arch
It has four centers.
Venetian arch comes under this category.
Another example is Tudor arch.
B.C.Punmia
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Reference-

24. Five-Centered Arch
It has five centers
Fives centers help in getting a good semi-elliptical shape
Reference-B.C.Punmia
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25. Classification Based On Material And
Workmanship
Stone Arch Brick Arch
Concrete ArchReference-B.C.Punmia
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26. Stone Arch
1.Rubble Arches
Weak and use for comparatively inferior
work.
Made by stones which are dressed, roughly
shaped and sized as voussoirs
Mortar is used for binding stones
2.Ashlars Arches
Made by stones which are fully dressed and
in proper shape of voussoir.
Lime or cement mortar is use as binding
material.
Use for making Flat arches
Reference-B.C.Punmia
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27. Brick Arches
1.Rough Arch
Made with ordinary bricks
Joints are wedge-shaped with
greater thickness at extrados and
smaller thickness at intrados.
Not used for exposed brick work.
2.Axed or Rough-cut Arch
Made with wedge shaped bricks
Joints are of uniform thickness.
Not so attractive due to wedge
shaped bricks which are not finely
dressed.
Reference-B.C.Punmia
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28. 3.Gauged Arch
Made with bricks which are prepared to
exact size and shape of voussoir.
Joints are fine , thin and truly radial.
Lime putty is use as a binding material.
4.Purpose made brick Arch
Made with special bricks which are
manufactured in exact shape and size of
voussoirs.
This is very fine workmanship.
Lime putty is used as a binding material.
Reference-B.C.Punmia
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29. Concrete Arches
1.Concrete block-unit Arch
Made with pre casted concrete
blocks.(moulds in shape of voussoirs)
Good appearance and size of arch
achieved due to perfections.
Cement mortar is used as a binding
material and joints are thin.
2.Monolithic Arch
Made with cast-in-situ concrete, either
plain or reinforced.
Suitable for large span.
The thickness is 15cm for arches upto
3m span.
Reference-B.C.Punmia
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