[0001] The present invention relates to a plinth.
[0002] Plinths are structures serving as bases or foundations, in particular to house pillars
or trestles.
[0003] In the specific case the object of the invention is a plinth that is circled, prefabricated
or cast in place.
[0004] Normally, such plinths have cubic or parallelepiped outer structure and they define
a cavity into which is inserted the pillar or trestle.
[0005] Prior art plinths internally present a double bracket reinforcement.
[0006] However, the aforesaid plinths have some drawbacks, both in relation to the high
cost of the inner reinforcement and to the time necessary for their preparation.
[0007] An additional drawback is that the structure in the shape of a cube or a parallelepiped
is not optimal from the viewpoint of distributing stress.
[0008] An object of the present invention is to eliminate the aforesaid drawbacks making
available a plinth that is more economical and at the same time more functional.
[0009] Said objects are fully achieved by the plinth of the present invention, which is
characterised by the content of the appended claims and in particular in that it has
such a shape as to present a circular or oval cross section with such a hoop as to
absorb tangential and torsion stresses.
[0010] The hoop is preferably constituted by a spiral with fixed pitch or variable pitch.
[0011] This and other characteristics shall become more readily apparent from the description
that follows of a preferred embodiment, illustrated purely by way of non limiting
example in the accompanying drawing tables in which:
- figure 1 shows a perspective view of the plinth;
- figures 2 and 3 show respectively a front and plan view, partially sectioned, of the
plinth;
- figure 4 shows a partially sectioned front view of the plinth, in an embodiment variant;
- figures 5 and 6 show respectively a front and plan view, partially sectioned, of the
plinth.
[0012] With reference to the figures, the number 1 indicates, in its entirety, a prefabricated
foundation plinth, comprising a main body or collar 2 having circular or oval cross
section and defining within it a cavity 3, preferably with cubic or parallelepiped
shape, shown in figure 1, into which a pillar is installed.
[0013] The main body thus has an original outer shape, substantially cylindrical or cone
frustum with the lower base upwards.
[0014] The plinth further comprises a base or slab 4 made of reinforced concrete for discharging
the stresses on the ground, which slab is an ordinary plinth base able to withstand
combined compressive and bending stresses as well as the punching by the pillar-plinth
complex.
[0015] Preferably the plinth 1 is a monolithic prefabricated plinth, i.e. one in which main
body and slab are prefabricated in a single piece.
[0016] However, the plinth can also be monolithic in place, i.e. with main body and slab
cast in place to form a single piece.
[0017] The main body of the plinth defines four blind holes 8, positioned at 90° and of
a substantially known type, separated by a thin baffle from the central cavity 3.
As the need dictates, it is easy to break one of the baffles to open one of the holes
8 creating a communication between the cavity 3 and the exterior of the plinth, through
which cables can be passed, for example.
[0018] The plinth, according to the embodiment variant shown in figure 4, may also be constituted
by a prefabricated main body that couples with a slab cast in place. In this case,
three irons 7 are used, preferably with 30 mm diameter, to hold the main body stably
in position while casting the slab.
[0019] The main body 2 is reinforced by a cage 5 originally constituted by individual vertical
and sub-vertical irons 9, whose function is to collaborate with the concrete to generate
and adequate resistance to axial and/or flexion stresses.
[0020] The irons 9 have 12-20 mm diameter and they are inferiorly bent for anchoring to
the slab.
[0021] The main body 2 further comprises a spiral 6, preferably made of reinforcement steel
having 10-16 mm diameter, which in addition to restraining the irons described above,
serves the purpose of withstanding tangential (horizontal) and/or torsion stresses.
[0022] The spiral 6 has substantially transverse development.
[0023] The spiral 6, at three or more turns with fixed pitch or with variable pitch, is
positioned in the upper part of the main body, whilst in the intermediate part of
the main body is present an intermediate hoop 10 preferably with a single turn and
in the lower part there can be a base hoop 11 to facilitate assembling the slab and
the main body.
[0024] In the slab, instead, there is a mesh reinforcement 12.
[0025] The present invention has the advantage of presenting a single spiral reinforcement
and single hoops instead of a double bracket reinforcement, with consequent saving
of about 30% of the ferrous material employed and about 50% of the time necessary
to install the plinth, both thanks to the smaller quantity of ferrous material used,
and because the spiral and the hoops are obtained from iron already bent circularly
because it is wound on reels, whilst traditional double bracket reinforcements, with
the irons bent repeatedly to describe substantially rectangular shapes, need more
time for working and bending the iron. This allows for evident savings in the costs
of manufacture of the plinth.
[0026] An additional advantage is that the particular cylindrical or cone frustum shape
of the main body 2 of the plinth, having perfect symmetry, allows for better functionality
of the plinth with respect to stresses.
1. A plinth, prefabricated or cast in place, characterised in that it has a main body (2) presenting circular or oval cross section and cylindrical
or cone frustum outer shape.
2. A plinth as claimed in claim 1, wherein internally to the main body (2) there is a
cage (5) that surrounds a cavity (3) and comprises a plurality of substantially vertical
irons (9) such as to absorb axial and flexion stresses and a spiral (6) with such
transverse development as to absorb tangential and torsion stresses.
3. Plinth as claimed in claim 2, wherein the spiral (6) has fixed pitch.
4. Plinth as claimed in claim 2, wherein the spiral (6) has variable pitch.
5. Plinth as claimed in claim 1, wherein is present a slab (4) with a mesh reinforcement
(12) in its interior.
6. Plinth as claimed in claim 1 or 2, wherein is present an intermediate hoop (10).
7. Plinth as claimed in claim 1 or 2, wherein is present a base hoop (11).
8. Plinth as claimed in claim 5, wherein the main body (2) is prefabricated and the slab
(4) is cast in place.
9. Plinth as claimed in claim 8, wherein the main body (2) comprises irons (7) to keep
the main body (2) stably in position during the casting of the slab (4).
10. Plinth as claimed in claim 2, wherein the substantially vertical irons (9) are single
irons.