Arches and beams

di Franco Laner

The observer seems to be asking: I have an arch over

the head? I reply with the following article.

My wife pointed out to me, in Facebook, some comments

about the Alvu nuraghe Pozzomaggiore, particularly of Saba friends

and Montalbano, together with others are questioning the construction of tecnemi

nuraghi, dry (there is no mortar and aggregates -that I can legante-

testify to having done analysis on alleged mortars of Losa) and blocks summarily

blanks.

I’m sorry to disappoint rather Auguadro colleague: if I had any credibility,

I would really change the history of architecture opening every story

generally with the well of S. Cristina, snatching archeology, that very little

It has to do with the wonderful and exciting constructed document.

However, the problem in question is a bit ‘more

intriguing than it might appear and especially the opinion of extemporaneous

those approaching to a discipline bearing the common sense is not enough (I

often done the praise of good common sense, citing Raffaele La Capria, which

in the beautiful booklet “The fly in the bottle” clarifies the importance of

common sense).

Sometimes it is, however,

You need to know the prolegomena of a scheme for making judgments more

depth.

There are two ways to cover a space: or with the “beam

simply supported “and its

declensions (in practice the trilith, as the dolmen) or “bow” that

however, it is pushing, unlike the simply supported beam which gives

vertical reactions.

The beam must be made with material that resists

compression and traction. Over instead it is sufficient that the material

resist compression. Every component, Ashlar, is just crushed, never

tense and in this fact lies the wonder of arch structures, in turn,

to rotation of the dome.

Meanwhile, first, never mind the priorities and historical dating,

because both solutions have historical precedents in various locations and

Also present at the community and non-contiguous territories, isolated from each other. IS’

how to argue about who “invented” the sloping pitched roof or floor …. us

are similar and obvious solutions at most different and isolated communities, because

man’s intelligence is widespread and solves the same, obvious way,

particular situations. For example, to let the water out and away

from the factory there that the sloping pitch.

 

natural arches. The corrosion by water and wind leaves

structures that naturally behaving arc (Devil’s Bridge in Paullo and

Lovers in Amalfi). There are many bridges to natural arch and can

have inspired the construction system

And so to cover a space: either you put a beam of

wood, or stone slab resting on the walls or the orthostats, or we resort

arc.

The latter solution is diabolical (the Arabs say the

hell invented the bow). Many naturally formed arches are

called the devil and bridges are beautiful legends about these bridges have

in the background the defeat of the devil. The Romans have led to remarkable

completion the arc technology, but they did not invent it. Remains of arches,

oltrettutto made without rib, are present in Middle Eastern territories

millenniums before Christ.

 

The figure that I have taken from “Voices of Technology

Architecture “and. Tecnologos, Mantua, 2006, concerning the item “Tecnema

and morpheme “, that I have taken care of

So notice the chatter.

While the formal visual point of view can be confused and

define each arc curved structure, from a structural point of view the

difference between bow and the beam is substantial: the beam transmits loads

vertical, the arch and pushes the thrust can be otherwise neutralized (eg.

with buttresses, with tie rods, with large pillars, etc.).

It is nevertheless quite clear that I am dealing with the topic

modern conceptual categories. It would be foolish to think about the technical solutions

of the past with our current categories. In other words the builders

nuragici had definitely not in the head, the beam, the arch, the reactions, the

stress, the force vector, or the concept of flexural … Rather

conceptions that to me at least definitely escape! Certainly possessed categories

constructive and practical magisteria to realize what has come to us.

In the case reported

niche dell’Alvu the situation is that of the flange, that is a

arch.

But at the same Alvu there are other situations: there is a

stone which rests on the tapered structure and especially another arch that

it is of course formed with a bedding.

Then there is the wonderful state of horizontal arch compulsion

the tholos, belongs to every nuraghe, which allows the self-construction of the

dome that I always tried to explain (v. “Accabadora” and “Sa ‘ena”) although

with little success.

This solution is the same as Brunelleschi adopted

for the Florentine dome and beautifully is mentioned in these movies

days “The Doctors”, when the director lingers with a recovery in the

Florentine dome came to the drum and shows the wireless network (the Magic Network

Brunelleschi) that will serve to plot the eight arches compulsion that

ally with gravity to achieve the dome without rib. But the invention

is Brunelleschi, or the Sardinians have preceded it? But also in the trulli is present

the same artifice, as well as in the ancient Abruzzo shelters … What meaning does

laughable claim of priority?

It is not enough to say that the Nuragic builders

brought the art of building dry at the highest teaching authority of this technology

and also that precisely in this report, for the most incomprehensible, resides the

nuragica particular culture?

Just understanding the thin frozen construction arcane

in nuraghi was the driving force that prompted me to write “Accabadora,

construction technology nuragiche “!

Poor those people who needs inventive priority

legitimize their cultural roots!

Do a little effort and read, although a little ‘

dated, the illuminating book by J. Diamond “Weapons, steel and” pocket diseases

Einaudi, 1998 and maybe you will better understand the issue of the pink jersey

often you want to wear to claim priority.

The first reference that comes to mind on the ridiculousness

of the claims, it is the priority of the stone statuary claimed by

giants of Monte Prama. But that’s another story!

Source Archeologia Nuragica