Arch is defined as a curved symmetrical structure lengthening an opening and usually supporting the weight of a bridge, roof, wall or load above it. There are two types of arches based on shape and number of centers.
( An arc is part of a circle’s circumference. An arch is a curved structure that lengths an opening and typically bears a bridge or roof.)
Types of Arches:
Types of arches are based on various types, some are defined below:
Types of Arches based on shape:
Depend on the shape of construction, arches are divided into 6 types and they are defined below:
1) Pointed Arch
The other name of the pointed arch is the Gothic arch. In the pointed arch, two arcs of circles are joint at the apex hence triangle is produced. This can be isosceles or equilateral.
2) Flat Arch
- For the flat arch, the intrados is apparently flat and it acts as a base of an equilateral triangle which was formed by the horizontal angle of 600 by skewbacks.
- Even though the intrados is flat but it is given that slight rise of a camber of about 10 to 15 mm per meter width of the opening is allowed for small settlements.
- Extrados is also horizontal and flat. These flat arches are usually utilized for light loads, and for lengths up to 150cm.
3) Florentine Arch
The interior curve of an arch is in the shape of the semi-circle and the remaining of the arch is the same as the Venetian arch. It has 3 centers, all fixed on the springing line.
4) Segmental Arch
- This is the simple type of arch utilized for buildings in which Centre of arch comes below the springing line.
- In the segmental arch, the thrust Transferred in inclined direction to the abutment.
5) Stilted Arch
Stilted Arch consists of a semi-circular arch with two vertical portions at the springings. The Centre of the arch comes on the horizontal line through the tops of vertical portions.
6) Semi-Circular Arch
The shape of the arch curve looks like a semi-circle and the thrust transferred to the abutments is perfectly vertical direction since skewback is horizontal. In this type of arch, the Centre comes exactly on the springing line.
Types of Arches based on number of Centers
Types of arch based on the number of centers the arches are divided as:
Segmental, semi-circular, flat, horseshoe arches and stilted arches are one centered arches. In a few cases, the perfectly circular arch is needed for circular windows which are called bull’s eye arch is also come under this group.
2)Two Centered Arches
Pointed or gothic or lancet arches usually lie under this type.
3)Three Centered Arches
Semi elliptical and Florentine arches are usually containing three number of centers.
4)Four Centered Arches
Venetian arch is a general example of a four-centered arch. The Tudor arch is also having four centers.
5) Five centered arches
A good semi-elliptical shape arch consists of five centers.
( For types of canal: Click here )