What is Arche? Parts Of Arch | Components Of Arch

What Is Arch?

Arch is a mechanical arrangement of wedge-shaped blocks of stones or bricks mutually supporting each other and supported at the end by piers or abutments.

In common with lintels, the function of an arch is to carry the weight of the structure above the opening. In this article we have discussed various parts and components of arch.

Parts Of Arch

The different parts of an arch are described below:

1. Abutment Or Pier

It is the part of the wall or pier on which the arch rests.

4. Extrados

It is the outer surface of an arch or the outer curve of the arch ring.

5. Voussoirs Or Arch Block

The wedge-shaped units forming the arch are known as voussoirs or arch stones or arch block.

6. Springing Stone

Springing stone or springer is the first voussoirs at springing level on either side of the arch.

7. Springing Line

Springing line is an imaginary line joining two springing points.

8. Crown

Crown is the highest point of the extrados or it is the highest part of the arch.

9. Key-stone

It is the highest central wedge-shaped block of an arch.

10. Skew-back

It is the surface of the abutment on which the arch rests.

11. Span

Span is the clear horizontal distance between supports.

12. Rise

Rise is the vertical distance between the springing line and the highest point on the intrados.

13. Springing Point

Springing points are the points at extremities of the intrados.

14. Depth Of Arch

The depth of the arch is the perpendicular distance between the intrados and the extrados.

15. Haunch

Haunch of the arch is the portion of the arch situated centrally between the key and skew backs.

16. Spandril

Spandril is the triangular walling enclosed by the extrados of the arch, a horizontal line from the crown of the arch, and a perpendicular line from the springing of the outer curves.