1. Prepared BY- Parth Chauhan - 130860106015
The Arch
Prepared BY-
Parth Chauhan

2. An arch is a curved structure capable of spanning a space while supporting significant weight (e.g. a doorway in a stone wall). It can also be called a curved lintel.
Early builders could span only narrow openings because of the necessary shortness and weight of monolithic stone lintels.

3. A Bit Of History
The arch was first developed in the Indus Valley civilization circa 2500 BC and subsequently in Mesopotamia, Egypt, Assyria, Etruria, and later refined in Ancient Rome.
Arches were used by some civilizations for underground structures such as drains and vaults, but the ancient Romans were the first to use them widely above ground.
The arch became an important technique in cathedral building and is still used today in some modern structures.

4. The invention of the arch solved to main problems:
Wide openings could be spanned with small, light blocks.
Brick as well as stone could be used, which made it easier to transport and handle.
The lintel was bent upward to resist and to conduct into its supports the load that tended to bend the lintel downward.

5. The arch's form create problems of equilibrium that don’t exist in lintels.
The stresses in the arch tend to squeeze the blocks outward, and loads divert these outward forces downward to exert a resultant diagonal force, called thrust.
If it’s not properly buttressed then the thrust will cause the arch to collapse.
Archs can be placed in a row, because the thrust of one arch counteracts the thrust of its neighbors.

6. It provides a structure which eliminates tensile stresses in spanning an open space. All the forces are resolved into compressive stresses.
This is useful because several of the available building materials such as stone, cast iron and concrete can strongly resist compression but are very weak when tension is applied to them.
The arch is a very useful structure as it is completely self-supporting. This is because all the compressive forces hold it together in a state of equilibrium.

7. Types of Arch
Shouldered flat arch

8. Construction
A simple way is to build a frame (usually made of wood) which follows the exact form of the underside of the arch. This process is known as a centre or centring.
The voussoirs are laid on it until the arch is complete and self-supporting. For an arch higher than head height, scaffolding would in any case be required by the builders. Occasionally arches would fall down when the frame was removed if construction or planning had been incorrect.
The size of the arch is limited only by economy.

9. A vault is an application of the arch extended horizontally; the groin vault is the intersection of two vaults.
A dome is a simple application of the arch, rotated about the center axis. Igloos are notable early structures making use of domes.
A special form of the arch is the triumphal arch, usually built to celebrate a victory in war. The most famous example of this is the Arc de Triomphe in Paris, France.

10. Natural rock formations may also be referred to as "arches"
Natural rock formations may also be referred to as "arches". These natural arches are formed by erosion rather than being constructed by man.

11. Modern Constructions Apollo, Bratislava, The Gateway Arch
in Saint Louis, Missouri
Apollo, Bratislava,
Slovakia
The New Svinesund Bridge
across the Ide fjord at Svinesund

12. THANK YOU