Importance of ARCH, AQUEDUCTS, DOMES, CANTILEVER

ARCH

The Importance of the arch is the strongest shape with the least amount of material known. The arch is also the only shape that can use single individual modules of materials, like brick and stone, and be used to span a distance that straight stone spans could never do. The span uses the compressive strength of stone and gravity to allow it to bridge large expanses without the tensile limit presented by the material itself.

 Arches have many forms such as a the Roman arch or clover arch. An arch works primarily in compression, and handles compressive loads, not tensile loads. 

AQUEDUCTS

   The importance of having aqueducts in a city such as Rome, was actually conducive to the city's growth. Fresh water was a major problem in many ancient cities. The natural water supply could usually support a limited number of people in many communities.

They may take the form of underground tunnels, networks of surface channels and canals, covered clay pipes or monumental bridges.  
(Ever since the human race has lived in communities and farmed the land, water management has been a key factor in the well-being and prosperity of a community).

Hugely ambitious engineering projects successfully mastered all kinds of difficult and dangerous terrain and made their magnificent arched aqueducts a common sight throughout their empire, supplying towns with water to meet not only basic needs but also those of large public baths, decorative fountains (nymphaea) and private villas.

Aqueducts were a means to transport water from one place to another, achieving a regular and controlled water supply to a place which would not otherwise have received sufficient water to meet basic needs such as irrigation of food crops and drinking fountains.

DOMES

Domes as large as fifty meters have been constructed in the wilderness from rough materials without a crane. The dome is also aerodynamic, so it withstands considerable wind loads, such as those created by hurricanes.

Of course, like all domes, geodesic domes provide an enclosed space free of structural supports. Domes are very strong, actually getting stronger as they get larger. The basic structure can be erected very quickly from lightweight pieces by a small crew.

CANTILEVER

Cantilever bridges are very common over roads. Because the beam is resting simply on the arms, thermal expansion and ground movement are fairly simple to sustain. More easily constructed at difficult crossings by virtue of using little or no falsework. Complex structures and can be dificult to maintain.

Cantilever arms are very rigid, because of their depth. Like beams, they maintain their shape by the opposition of large tensile and compressive forces, as well as shear, and are therefore relatively massive. Truss construction is used in the larger examples to reduce the weight.

 Cantilevers are supported on only one end. They have some architectural advantages. In real life, we usually build cantilever structures when it is impractical to support both ends. Sometimes there are other reasons - such as aesthetics or functionality of the space beneath the structure. 

 Cantilevers are very flexible and can bend under heavy loads if they are in one spot. They use expensive foundation work with all the load going on if in soft ground.

FRANCIS EMERSON NASTOR QUIOBE