This document summarizes the different types and components of masonry arches. It describes arches based on their shape, including flat arches, segmental arches, semicircular arches, horseshoe arches, pointed arches, Venetian arches, Florentine arches, relieving arches, and stilted arches. It also categorizes arches based on the number of centers, including one-centered, two-centered, and three-centered arches. The document concludes by defining the key components of masonry arches, such as the abutment, arch, crown, extrados, intrados, keystone, label course, rise, skewback, sp

1. DR. AMBEDKAR INSTITUTE OF TECHNOLOGY
(AN AUTONOMOUS INSTITUTION, AFFILIATED TO V.T.U)
BANGALORE-560056
Seminar On Masonry Arches- Components & Classiification
Submitted By:
Akif Perwez
(1DA19CSE01)

2. INTRODUCTION
A curved masonry construction for spanning
an opening, consisting of a number of
wedge
like stones, bricks, or the like, set with the
narro w side toward the opening in such
away that for ces on the arch are
transmitted as vertical or ob lique stresses
on either side of the opening.

3. TYPES OF
MASONRY
ARCHES

4. BASED ON SHAPE: FLAT ARCH
In this the intrados is apparently flat and it
acts as a base of equilateral triangle which
was formed by the horizontal angle of
600by skewbacks.
Extrados is also horizontal and flat.
These flat arches are generally used for
light loads, and for spans up to 1.5m.

5. SEGMENTAL ARCH
This is the basic type of arch used for
buildings in which Centre of arch lies below
the springing line.
In segmental arch, the thrust Transferred
in inclined direction to the abutment.

6. SEMI-CIRCULAR ARCH
The shape of arch curve looks like semi-
circle and the thrust transferred to the
abutments is perfectly vertical direction
since skewback is horizontal.
In this type of arch, the Centre lies
exactly on the springing line.

7. HORSE SHOE ARCH
Horse Shoe Arch is in the shape of horse
shoe which curves more than semi-circle.
This is generally considered for
architectural provisions.

8. POINTED ARCH
It is also known as Gothic arch.
In this type of arch two arcs of circles are
met at the apex hence triangle is formed.
This may be either isosceles or equilateral.

9. VENETIAN ARCH
It is also pointed arch but its crown is
deeper than springing.
It contains four Centre’s, all located on
the springing line

10. FLORENTINE ARCH
Intrados of arch is in the shape of semi-circle
and rest of the arch is similar to Venetian
arch.
It has three Centre’s, all located on
the springing line.

11. RELIEVING ARCH
It is constructed above flat arch or on a wooden lintel to provide greater
strength.
In this, we can replace the decayed wooden lintel easily
without disturbing the stability of structure.
The ends of this arch should be carried sufficiently
into the abutments.

12. STILTED ARCH
It consists of a semi-circular arch with
two vertical portions at the springing.
The Centre of arch lies on the horizontal
line through the tops of vertical portions.

13. SEMI-ELLIPTICAL ARCH
This is a type of arch of semi-ellipse shape
and having three or five Centers.

14. BASED ON NUMBER OF CENTRES –ONE
CENTERED ARCHES
Segmental, semi-circular, flat, horse-shoe
arches and stilted arches are one centered
arches.
In some cases, perfectly circular arch is
provided for circular windows which is called
as bull’s eye arch is also come under these
category.

15. TWO CENTERED ARCHES
Pointed or gothic or lancet arches
are generally come under this type.
Three Centered Arches
Semi elliptical and Florentine arches
are generally having three number
of centers

16. COMPONENTS
OF
MASONRY ARCHES

18. Parts of Arches

19. Abutment:
The masonry or combination of masonry and other structural members which support one end of the arch at the
skewback.
Arch:
A form of construction in which masonry units span an opening by transferring vertical loads laterally to adjacent
voussoirs and, thus, to the abutments.
Camber:
The relatively small rise of a jack arch.
Centering:
Temporary shoring used to support an arch until the arch becomes self-supporting.
Crown:
The apex of the arch's extrados. In symmetrical arches, the crown is at the midspan.

20. Depth:
The dimension of the arch at the skewback which is perpendicular to the arch axis, except that the depth
of a jack arch is taken to be the vertical dimension of the arch at the springing.
Extrados:
The curve which bounds the upper edge of the arch.
Intrados:
The curve which bounds the lower edge of the arch. The distinction between soffit and intrados is that the
intrados is a line, while the soffit is a surface.
Keystone:
The voussoir located at the crown of the arch. Also called the key
Label Course: A ring of projecting brickwork that forms the extrados of the arch.

21. Rise:
The maximum height of the arch soffit above the level of its spring line.
Skewback:
The surface on which the arch joins the supporting abutment.
Skewback Angle:
The angle made by the skewback from horizontal.
Soffit:
The surface of an arch or vault at the intrados.
Span:
The horizontal clear dimension between abutments.

22. Spandrel:
The masonry contained between a horizontal line drawn through the crown and a vertical line drawn through the upper
most point of the skewback.
Springing:
The point where the skewback intersects the intrados.
Springer:
The first voussoir from a skewback.
Spring Line:
A horizontal line which intersects the springing.
Voussoir:
One masonry unit of an arch.

23. THANK YOU