Roselys Acosta Cristina Montoya

shrubflattenUrban and Civil

Nov 25, 2013 (3 years and 9 months ago)

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Roselys Acosta

Cristina Montoya

The simplest illustration of load and
support in construction is the post and
lintel system in which two upright
members vertically (posts, columns,
piers) placed and a third member
(lintel, beam, girder, rafter) laid
horizontally across their top surfaces.


In its pure form, the post and lintel is seen only in colonnades and in frame
structures, since the posts of the doors, window, ceilings and roofs are part of
the wall.

The biggest disadvantages to this type of construction is the limited weight that
can be held up, and the small distances required between the posts.
Roman

developments of the
arch

allowed for much larger structures to be constructed.

There are two main forces acting upon the post and lintel:
compression

and
tension
. The two posts are under compression from the weight of the lintel (or
beam) above.
The underside of the lintel is under tension, while the topside is
under compression.

A
lintel

or
header

is a horizontal
beam

used in
the construction of
buildings
, and is a major
architectural contribution of ancient Greece. It
usually supports the
masonry

above a
window

or
door

opening. (Also sometimes spelled
'lintol', 'lintil',' lyntil'.)

we use it to bear the loads that rest on it without deforming or breaking. Its
weakness is failure in certain loads.

Lintels may be made of
wood
,
stone
,
steel

or
reinforced

or
pre tensioned
concrete
.

For example, at
Stonehenge
, stone lintels top
off some of the
megaliths
. In typical homes
today, lintels are commonly used in
fireplaces

where one will span the opening of the firebox.
In this use they are most often steel, either
straight for a square opening or arched for a
more decorative effect.

we use it to support the lintel and loads without
crushing or bulking. Its weakness failure occurs
as in lintels from excessive weakness or length
but the difference is that material must be
especially strong in compression.

Stone which has this property is more versatile
as a post than as a lintel; under heavy loads it is
superior to wood but not to iron, steel, or
reinforced concerte.

From prehistoric times to the roman empire, the post and lintel
system was the roof of architectural design
.

Dolmens are the primary way to express how the
prehistoric man made the first post and lintel.


we can see the entrances of temples, the
used post in a decorative form, as figures
that protect the inside of the temples.
Also the interiors of Egyptian temples are
delineated by columns covered by stone
lintels


facade of the temples mostly all three of them have
stone materials, the spans given by these system is
too small and that’s why they invented arch.


In architecture, a
trabeated

system or order (from
Latin

trabs
,
beam
; influenced by
trabeatus
, clothed in the
trabea
, a ritual
garment) refers to the use of horizontal beams or
lintels

which
are borne up by
columns

or posts. It is the opposite of the
arcuated system, which involves the use of arches.

The trabeated system is the fundamental principle of
neolithic
architecture
,
Ancient Greek architecture

and
Ancient Egyptian
architecture
. Other trabeated styles are the
Persian
, Lycian,
nearly all the
Indian

styles, the
Chinese
,
Japanese

and South
American styles.

In India the style used origninally for wooden constructions, but
later the technique was adopted for stone structures.

Post
-
and
-
lintel solutions can be executed in various materials, but gravity
subjects the horizontal members to bending stress, in which parts of the
member are in compression while others are in tension. Wood, steel, and
reinforced concrete are efficient as beams, whereas masonry, because it
lacks tensile components, requires much greater bulk and weight. Vaulting
permits spanning without subjecting material to tension; thus, it can cover
large areas with masonry or concrete. Its outward thrust, however, must be
counteracted by abutment, or buttressing.

Ancient uses of the post and lintel were refined but not
fundamentally altered until the production of cast


iron
columns, which, offering greater strenght and smaller
circunference, greatly reduced the mass and weight of
buildings. Much construction in modern materials is
based on the post and lintel system of the post. Steel
and concrete skeletons restore to modern architeture to
formal simplicity of the oldest structures known. But,
because they are rigid frames, they abandon the
fundamental concept of the duality of post and lintel by
fusing the into a unit through which stresses are
distributed.