TECHNICAL FIELD
[0001] The present invention relates to a foundation or a pile driven foundation for an
overhead line mast, power line mast or the like, comprising a reinforced concrete
pile including threaded bolt connectors, a number of gaskets and a corresponding number
of tightening nuts.
BACKGROUND OF THE INVENTION
[0002] Prefabricated concrete piles are normally used for foundations at location where
the upper soil layers are not suitable for accommodating a shallow foundation. At
location where the bearing capacity of the ground is weak in relation to the construction,
piles are preferred option compared to shallow foundations. Through the use of a piling
foundation the load from the construction may be transferred from the weaker upper
layers of the soil to lower stronger layers, which are typically found deeper level
in the ground. The piles are driven into the ground by using a pile driver or hammer
or the like.
[0003] The piles are intended for embedment deep into the ground for providing a stable
foundation for various structures such as buildings, bridges and similar constructions.
The pile foundation can be used in soil layers along railways.
[0004] For purposes where prefabricated concrete foundations used with threaded bolt connections
it is necessary to protect the reinforcement from water penetrating into the concrete
at the bolt shaft. The water will penetrate the foundations, more precisely the water
will penetrate into the reinforced concrete piles between the bolt shaft and the reinforcing
concrete causing the reinforcement elements of the reinforced concrete piles to corrode
and eventually cause the reinforced concrete supporting the bolt shaft to break, which
will reduce the stability of the overlying construction. The penetrating water may
also freeze when subjected to temperatures below 0° C and cause damage to the pile.
There is consequently a need for technologies for avoiding water penetration into
the concrete foundation, especially reinforced concrete bolt-foundations for railway
powerlines, or similar with demand for long durability being exposed to outside weather
conditions.
[0005] The general object of the present invention is to provide a prefabricated reinforced
concrete pile, which is able to withstand the environment impact and exposure occuring
over time on the structure at the installation location.
[0006] The above need and object together with numerous other needs and objects, which will
be evident from below detailed description, are according to a first aspect of the
present invention obtained by a foundation for an overhead line mast, power line mast
or the like, comprising a reinforced concrete pile including threaded bolt, a number
of gaskets and a corresponding number of tightening nuts:
- the reinforced concrete pile defining an elongated structure having a first end part
including a planar abutment surface of a first polygonal geometry and a second end
part, steel reinforcement elements extending between the first end part and the second
end parts, the threaded bolt connectors being embedded in the reinforced concrete
pile and each having an exposed part extending beyond the first end part and positioned
in a second polygonal geometry and connected to the steel reinforcement elements of
the reinforced concrete pile, the second polygonal geometry being equivalent to the
first polygonal geometry,
- each of the exposed part of the threaded bolt connectors having a first portion including
a threaded portion, a second portion having a circular cross sectional configuration
of a first outer diameter and a transition portion interconnecting the first portion
and the second portion,
- a first interface being located between the first portion and the transition portion
of each of the threaded bolt connectors at a first distance from the planar abutment
surface,
- a second interface being located between the transition portion and the second portion
of each of the threaded bolt connectors at a second distance from the planar abutment
surface, the first distance being larger than the second distance,
- each of the gaskets having an annual shape forming a second inner diameter and second
outer diameter,
- the tightening nuts having a first end surface, a second end surface and a central
aperture including a tapered portion at the second surface end for providing a larger
opening compared to the central aperture, the central aperture further including a
third internal threaded portion at the first end surface complimenting the threaded
portion of the threaded bolt connectors,
- the second inner diameter of the gasket being congruent to the first outer diameter
of each of the second portions of each the threaded bolt connectors and the second
outer diameter being larger than the inner diameter of the third internal threaded
part of the tightening nuts,
- the tightening nuts being configured to be rotated relative to the threaded portion
of the threaded bolt connectors for allowing the gaskets to be compressed towards
the threaded bolt connectors, the inner tapered portion of the tightening nuts and
the planar abutment surface for providing sealing relative to the threaded bolt connectors
and the planar abutment surface.
[0007] The reinforced concrete pile is an elongated prefabricated concrete pile. The reinforced
concrete pile is provided in various lengths.
[0008] The threaded bolt connectors would preferably be made from a stainless steel material,
as the threaded bolt connectors are exposed to the environment and have to be able
to withstand the weather. Stainless steel is the preferred material due to its corrosion
resistance as stainless does not corrode or rust as ordinary steel (carbon steel)
does. However, it is possible to use carbon steel for the steel reinforcement elements
as the steel reinforcement element are embedded into the reinforcement concrete pile,
[0009] The gasket is preferably made from an elastomer material with a round cross-section
and being designed to be compressed during assembly and would create a sealing at
the interface between the plain unthreaded surface of the threaded bolt connectors
and the planar abutment surface. Each gasket has an annual shape forming a second
inner diameter being congruent to the first outer diameter of the threaded bolt connectors
and second outer diameter being larger than the inner diameter of the third internal
threaded part of the tightening nut.
[0010] Each of the tightening nuts is configured to be rotated relative to the threaded
portion of a threaded bolt connector and by rotating the tightening nut, the tapered
portion of the tightening nuts will be moved towards the gasket. Rotation of the tightening
nut would cause the gasket to be compressed towards the outer surface of the threaded
bolt connectors and the planar abutment surface and the compression of the gasket
will provide a sealing between the threaded bolt connectors and the planar abutment
surface.
[0011] In a further embodiment according to the first aspect, the transition portions have
threaded portions being tapered over two revolutions from a fully threaded shaft to
a plain unthreaded shaft. Through the use of threaded bolt connectors having a threaded
portions being tapered over two revolutions from a fully threaded shaft to a plain
unthreaded shaft, it is possible to obtain a sealing for preventing water to penetrate
into the structure.
[0012] In a further embodiment according to the first aspect, the central aperture of the
tightening nuts have an intermediate section having a second threaded section, the
second threaded section extending between the tapered portion and the third internal
threaded portion, the second threaded section having a diameter being larger than
the threaded diameter of the third internal threaded portion. Through the use of tightening
nuts having a second threaded section with a diameter being larger than the inner
diameter of the third internal threaded portion, it is possible for the tightening
nut to be rotated beyond the threaded portion of the threaded bolt connectors. The
second threaded section being an inner threaded section and the diameter of the second
threaded section corresponds to the major diameter.
[0013] In a further embodiment according to the first aspect, the third internal threaded
portion is tapered over two revolutions. Through the use of tightening nuts having
third internal threaded portion being tapered over two revolutions, it is possible
to improve the sealing capability further and prevent penetration of water into the
reinforced concrete pile.
[0014] In a further embodiment according to the first aspect, the second portions of the
threaded bolt connectors are plain unthreaded portions. By using threaded bolt connectors
with second portions having a plain unthreaded surface, it is possible to enhance
the sealing capability at the interface between the outer surface of the gasket and
the plain surface of the threaded bolt connectors. The plain contact surface improves
the sealing capability compared to a threaded contact surface, hereby serving a first
function. The plain unthreaded portion of the threaded bolt connectors will prevent
the gasket from getting damaged or torn during tightening of tightening nuts during
installation, where the overhead line mast is installed on top of the reinforced concrete
pile, hereby serving a second function.
[0015] In a further embodiment according to the first aspect, the reinforcement elements
include additional steel reinforcement elements extending in the circumference of
the reinforced concrete. By using an additional steel reinforcement element extending
in the circumference, it is possible to obtain a steel mesh structure, which allows
easier handling and positioning of the steel mesh structure during casting and fabrication
of the reinforcement concrete pile. The of additional steel reinforcement elements
forms a steel mesh or mesh cage together with the steel reinforcing bar.
[0016] The mesh cage or reinforcement cage consists of two parts: longitudinal bars and
transverse bars or spiral bar. The steel bar has vertical rib and transverse rib on
the surface for better application in concrete reinforcement and the steel bar is
preferable made from cold drawn or hot drawn carbon steel wire rod, galvanized or
mill black finish.
[0017] The longitudinal steel bars confine the core concrete, and the transverse steel bars
or spiral bars fit around the longitudinal bars. The steel mesh cage provides reinforcement
in the longitudinal and lateral strength to prevent cracking, and reduce the deflections
occurrence probability.
[0018] The reinforcement cage has a polygonal geometry e.g. triangle or square and the reinforcement
cages is positioned in the casting mould before the concrete is poured the casting
form. The steel reinforcement elements are spot welded to form a reinforcement cage,
preferably by an automatic spot welding machine and the spot welding machine furthermore
is able to program for being able to adjust the spacing and opening of the reinforcement
cage.
[0019] In a further embodiment according to the first aspect, the reinforced concrete pile
is a prefabricated structure. Through the use of a prefabricated reinforced concrete
pile, it is faster to establish the foundation as the reinforced concrete does not
need to casted in-situ and await the hardening of the concrete before the overhead
line mast can be connected to the foundation.
[0020] In a further embodiment according to the first aspect, the second polygonal geometry
and the first polygonal geometry being 3-12, preferably 4. By using a polygonal geometry
it is optional, where the geometry should be rectangular, pentagonal, hexagonal etc.
[0021] In a further embodiment according to the first aspect, the reinforced concrete pile
have visual markings on the outer surface for positioning the end part 0.1-1 meter
above ground level, when the reinforced concrete pile is being driven into the ground.
By using visual markings on the reinforced concrete pile, the installation of the
reinforced concrete pile can be done in a more precise manner, as the worker at the
installation site can visual determine and inspect whether the reinforced concrete
pile needs to be driven further into the ground.
[0022] In a further embodiment according to the first aspect, the threaded bolt connectors
are connected to the steel reinforcement elements of the reinforced concrete pile
by welding, preferably friction welding. By welding the threaded bolt connectors to
the steel reinforcement bars, the structural loads from the mast can be transferred
from the threaded bolt connectors to the steel reinforcement elements embedded in
the reinforced concrete pile.
[0023] The term pile foundation should in this context be understood as a prepared ground
or base on which the overhead line mast, the power line mast or the like structure
can be mounted. The pile foundation consists of an elongated structural element being
driven or drilled into the deep of the ground and belong to the category also referred
to as deep foundation.
[0024] The term deep foundation should in the context be understood as the type of foundation,
which transfers load into the soil farther down from the ground level in contrast
to shallow foundation, which primarily transfers loads from the structure to the surface
layer at the vicinity of the ground level.
[0025] The term congruent is used in this context to describe a gasket being able to provide
a tight fit relative to the outer diameter of the second portion of the threaded bolt
connectors. Each gasket would have an inner diameter being identical to the outer
diameter of the second portion of each of the threaded bolt connectors or an inner
diameter substantial smaller than the outer diameter of the second portion of each
of the threaded bolt connectors.
[0026] The term internal threaded portion is used in this context to describe an internal
thread of the tightening nut is divided into two sections, which both have a major
diameter and a minor diameter. The diameter of the internal threaded portion would
in this context refer to the major diameter.
[0027] Although the invention has been described above with reference to a number of specific
and advantageous embodiments, it is to be understood that the present invention is
by no means limited to the above disclosure of the above described advantageous embodiments,
as the features of the above-identified embodiments may be combined to provide additional
embodiments. The additional embodiments are all construed to be part of the present
invention. Furthermore, the present invention is to be understood encompassed by any
equivalent or similar structure as described above and also to be encompassed by the
scope limited by the below claims defining the protective scope of the present patent
application.
DETAILED DESCRIPTION
[0028] The invention will now be explained in more detail by means of examples of embodiments
with reference to the schematic drawing.
Figure 1 shows a foundation installed along a railway track.
Figure 2 shows of a first and presently preferred embodiment of the reinforced concrete
pile.
Figure 3 shows the steel reinforcement elements embedded inside the reinforced.
Figure 4A-4D shows the tightening of the tightening nut.
Figure 5A-5E shows a first and presently preferred embodiment of the threaded bolt
connectors and a tightening nut.
Figure 6A-6D shows a second preferred embodiment of casting a reinforced concrete
pile according to first embodiment of the invention.
[0029] Fig. 1 shows foundation 10 comprising a reinforced concrete pile 20 having threaded
bolt connectors for allowing an overhead line mast 12 to be connected to the reinforced
concrete pile 20 of the pile foundation.
[0030] The overhead power line 16 is suspended above the railway track 14 between the overhead
line mast, supporting posts or arched catenary support or other carrying structures
spaced along the railway track 14. The overhead power line 16 is kept at a high electric
potential for suppling electric power to the train. The reinforced concrete pile 20
penetrates the upper soil layers and will be embedded in the lower, more rigid lower
soil layers. The reinforced concrete pile 20 is a precasted element and the reinforced
concrete pile 20 is casted in a standardized length between 4 meter and 20 meter.
[0031] Figs. 2 and 3 show a reinforced concrete pile 20 having an elongated structure with
a first end part 22 including a planar abutment surface of a first polygonal geometry
and a second end part 26. Steel reinforcement elements 28 extend between the first
end part 22 and the second end parts 28.
[0032] Four threaded bolt connectors 30 are embedded in the reinforced concrete pile 20
and each of threaded bolt connectors 30 has an exposed part extending beyond the first
end part 22. The four threaded bolt connectors 30 are positioned in a second polygonal
geometry and connected to the steel reinforcement elements 28 of the reinforced concrete
pile 20.
[0033] The connection between each of the threaded bolt connectors 30 and the steel reinforcement
elements 28 of the reinforced concrete pile 20 is obtained by welding process e.g.
friction welding and the connection will be embedded inside the reinforced concrete
pile 20. The threaded bolt connectors 30 would be made from a stainless steel material,
as the threaded bolt connectors are exposed to the environment and have to be able
to withstand the corrosion.
[0034] The steel reinforcement elements 28 are fabricated from an assembly of steel reinforcing
bar 28', also commonly referred to as rebars, held together in the desired configuration
by means of additional steel reinforcement elements 28" extending in the circumference
of the reinforced concrete pile 20. The additional steel reinforcement elements 28"
form a steel mesh or mesh cage incorporation with the steel reinforcing bar 28'.
[0035] Two lifting sockets 29 are embedded into the reinforced concrete pile 20 and the
lifting sockets 29 are placed at equal distance from the center of gravity of the
reinforced concrete pile 20 for allowing as stable lifting of the reinforced concrete
pile 20. Each of the lifting sockets 29 is connected to the steel reinforcement elements
28 by welding.
[0036] The lifting sockets 29 comprise an inner threaded portion and the threaded portion
makes it possible for a worker to insert a swivel lifting eye into the lifting socket
prior to lifting the reinforced concrete pile 20. The lifting socket could also be
formed as tubular lifting socket, flat plate lifting socket or the like. Each of the
lifting sockets 29 is covered by a sealing cap for preventing any foreign objects
from entering the socket and the sealing cap fits inside the lifting socket 29.
[0037] The steel reinforcement elements 28 have the same polygonal geometry as the reinforced
concrete pile 20 and the 28' steel reinforcing bars are placed along the circumference
of the reinforced concrete pile 20 more specific near the edges of the polygonal geometry.
[0038] The second polygonal geometry is defined by the number of threaded bolt connectors
embedded in the reinforced concrete pile 20 and the first polygonal geometry corresponds
the outer geometry of the reinforced concrete pile 20. The first polygonal geometry
is equivalent to the second polygonal geometry in fig. 2.
[0039] It is contemplated, that the tightening the tightening nut 501, 502, 503, 504 can
be done in two steps, 'Initial Torque' and 'Final torque' using a calibrated torque
wrench. This can be either a manual wrench or power tool fitted with a torque cut-out
that must first be calibrated on a bolt from the job batch using a bolt load meter
or similar device for determining bolt tension.
[0040] Figs. 4-5 show the threaded bolt connector 30 having a first portion 32 including
a threaded portion 33, a second portion 34 having a circular cross sectional configuration
of a first outer diameter and a transition portion 38 interconnecting the first portion
32 and the second portion 32. The gaskets 40 having an annual shape forming a second
inner diameter 42 and second outer diameter 44.
[0041] Fig. 4A shows threaded bolt connector 30 connected to the steel reinforcement elements
28 in the reinforced concrete pile 20. The second portion 34 of the threaded bolt
connector 30 has a circular cross sectional and the second portion 34 is connected
to the steel reinforcing bar 28' by welding. The second portion 34 of the threaded
bolt connector 30 has a plain unthreaded portion. 6. The steel reinforcement elements
28 comprising of a number of steel reinforcing bars 28' and additional steel reinforcement
elements 28" extending in the circumference of the reinforced concrete pile 20. The
additional steel reinforcement elements 28" form a steel mesh or mesh cage incorporation
with the steel reinforcing bar 28'.
[0042] In fig. 4A-4D, the gasket 40 has a second inner diameter 42 being congruent to the
first outer diameter of the second portions 36 of the threaded bolt connector and
the second outer diameter 44 is larger than the inner diameter of the third internal
threaded part of the tightening nuts 59.
[0043] In Fig. 4D, the first interface 60 is located between the first portion 32 and the
transition portion 38 the threaded bolt connector at a first distance d
1 from the planar abutment surface 24. The second interface 62 is located between the
transition portion 38 and the second portion 34 of the threaded bolt connector 30
at a second distance d
2 from the planar abutment surface 24
[0044] As indicated in fig. 4D, the first distance d
1 is larger than the second distance d
2 and the second distance d
2 is also larger the height h
g of the gasket. The height h
g of the gasket 40 corresponds to the thickness of the gasket 40. The second portion
34 of the threaded bolt connector 30 has a plain unthreaded portion, which will prevent
the gasket 40 from getting damaged or torn during tightening of tightening nut 50
during installation of the mast on top of the reinforced concrete pile.
[0045] Fig. 4B-4D shows the sequence of tightening the tightening nut 50, where the tightening
nut is configured to be rotated relative to the threaded portion of the threaded bolt
connector.
[0046] Fig. 4B shows the tightening nut 50, where the tightening nut 50 does not exert any
compression force on the gasket 40 and the gasket 40 is positioned around the plain
unthreaded portion of the threaded bolt connector 30 and abuts the planar abutment
surface of the first end part 22.
[0047] Fig. 4C shows the tightening nut 50, where the tightening nut 50 is rotated further
towards the planar abutment surface of the first end part 22. The tightening nut 50
begins to compress onto the gasket 40. The gasket 40 is positioned around the plain
unthreaded portion of the threaded bolt connector 30 and abuts the planar abutment
surface of the first end part 22.
[0048] Fig. 4D shows a final position, where the tightening nut 50 is rotated relative to
the threaded portion of the threaded bolt connector 30 to the position, where the
tightening nut 50 exerts the full compression load on the gasket. The amount of load
on the gasket 40 causes the gasket to deform and the deformation of the gasket results
in the gasket 40 being compressed towards the threaded bolt connectors, the inner
tapered portion 55 of the tightening nuts and the planar abutment surface 24 for providing
sealing relative to the threaded bolt connector 30 and the planar abutment surface
24.
[0049] As shown in fig. 5B, the tightening nut 50 has an intermediate section including
a second threaded section 56 and the second threaded section 56 extends between the
tapered portion 55 and the third internal threaded portion 58. The second threaded
section 56 has a threaded diameter d
4 being larger than the threaded diameter d
3 of the third internal threaded portion 58. By using a tightening nut 50 having an
inner second threaded section 56 having a threaded diameter d
4 being larger than the inner diameter d
3 of the third internal threaded portion, it is possible for the tightening nut 50
to be rotating beyond the threaded portion 33 of the threaded bolt connectors. The
second threaded section being an inner threaded section and the threaded diameter
corresponds to the major diameter of an internal thread.
[0050] As indicated in fig. 5B-5D, the tightening nut has first end surface 51, a second
end surface 52 and a central aperture 54 including a tapered portion 55 at the second
end surface 52 for providing a larger opening compared to the central aperture.
[0051] The central aperture 54 further includes a third internal threaded portion 58 at
the first end surface 54 complimenting the threaded portion 33 of the threaded bolt
connector 30.
[0052] Fig. 5D shows a first embodiment of the tightening nut 50 having a third internal
threaded portion being tapered over two revolutions.
[0053] Fig. 5C shows a first embodiment of the transition portions having threaded portions
being tapered over two revolutions from a fully threaded shaft to a plain unthreaded
shaft.
[0054] Fig. 6A-6D shows a second preferred embodiment of casting of the reinforced concrete
pile. The method of casting a reinforced concrete pile for a foundation, wherein the
foundation comprising a reinforced concrete pile including threaded bolt connectors,
a number of gaskets and a corresponding number of tightening nuts, comprising the
step of:
- providing a casting mould 70 having two mould side walls 72, a first mould end part
74 including apertures 75, a second mould end part 76 and a bottom mould part 78,
- inserting a number of anti-adherent elements 80 made of a synthetic material, Teflon
or the like into the apertures 75 of the first mould end part 74,
- placing steel reinforcement elements into the casting mould, the steel reinforcement
elements extending between the first end part and the second end parts of the casting
mould and a number of threaded bolt connectors being connected to the steel reinforcement
elements and allowing the threaded bolt connectors to extend beyond the first mould
end part,
- pouring concrete into the casting mould.
- casting a reinforced concrete pile defining an elongated structure having a first
end part including a planar abutment surface of a first polygonal geometry and a second
end part, steel reinforcement elements extending between the first end part and the
second end parts, the threaded bolt connectors being embedded in the reinforced concrete
pile and each having an exposed part extending beyond the first end part and positioned
in a second polygonal geometry and connected to the steel reinforcement elements of
the reinforced concrete pile, the second polygonal geometry being equivalent to the
first polygonal geometry.
[0055] By using a number of anti-adherent elements 80 made of a synthetic material, Teflon
or the like into the apertures 75 of the first mould end part 74, it is possible to
establish a reinforced concrete pile having a smooth planar abutment surface. By having
a smooth planar abutment surface, the sealing capability is enhanced and the smooth
surface of first end part 22 prevent water from gathering in void created in an otherwise
uneven first end part 22.
[0056] In figure 6A-6D, the four threaded bolt connectors 30 are placed in the casting mould
70 and each of threaded bolt connectors 30 has an exposed part extending into the
apertures 75 of the first mould end part 74 and beyond the first end part 22.
[0057] The steel reinforcement elements 28 consists of steel bars 28' 28" forming a steel
reinforcement cage 28'" fabricated from an assembly of longitudinal steel reinforcing
bar 28' and transverse steel reinforcement bar 28" extending in the circumference
of the reinforced concrete pile 20. The four threaded bolt connectors 30 are positioned
in a second polygonal geometry and connected to the steel reinforcement bars 28' of
the steel reinforcement cage. The steel reinforcement cage 28'" forms a recgtangular
polygonal geometry.
[0058] Two lifting sockets 29 are placed at equal distance in the casting mould 70 and the
lifting sockets 29 is connected to the steel reinforcement elements 28 by welding.
[0059] The lifting socket 29 comprises an inner threaded portion and the threaded portion
makes it possible for a worker to insert a swivel lifting eye into the lifting socket
prior to lifting the casted reinforced concrete pile 20 out of the casting mould 70.
[0060] The casting mould 70 is used for casting reinforced concrete pile 20 having an elongated
structure with a first end part 22 including a planar abutment surface of a first
polygonal geometry and a second end part 26.
[0061] The reinforced concrete piles are preferably precasted concrete elements manufactured
in at a larger manufacturing facility and delivered, ready to use, to the installation
site. Pre-casted reinforced concrete piles can also be fabricated on site and tilted
or lifted into position.
[0062] Fig. 6A shows the step of placing the steel reinforcement cage 28'" into the casting
mould 70 and steel reinforcement cage 28" comprising of a number of steel reinforcing
bars 28' and additional steel reinforcement elements 28" extending in the circumference
of the steel reinforcement cage 28"'.
[0063] The insert 80 is made of anti-adherent synthetic material, without or with a built-in
supporting body, made of metal or synthetic material.
[0064] The method further comprising the step of:
- arranging the threaded bolt connectors in the casting mould for providing a reinforced
concrete pile having a first interface being located between the first portion and
the transition portion of each of the threaded bolt connectors at a first distance
from the planar abutment surface, and a second interface being located between the
transition portion and the second portion of each of the threaded bolt connectors
at a second distance from the planar abutment surface, the first distance being larger
than the second distance,
REFERENCE NUMBERS
[0065]
10 foundation
12 mast
14 railway track
16 overhead line, power line mast or the like,
18 support structure
20 reinforced concrete pile
22 first end part
24 planar abutment surface
26 second end part,
28 steel reinforcement elements
28' steel reinforcing bar
28" additional steel reinforcement elements
steel reinforcement cage 28"'
29 lifting socket
30 threaded bolt connectors
31 exposed part
32 first portion,
33 threaded portion
34 second portion
36 first outer diameter of the second portion
38 transition portion
40 gaskets
42 second inner diameter
44 second outer diameter
50 tightening nut
501, 502, 503, 504 tightening nuts
51 first end surface
52 second end surface
54 central aperture
55 tapered portion
56 second threaded section
57 intermediate section
58 third internal threaded portion
59 inner diameter of the third internal threaded
60 first interface
62 second interface
d1 first distance
d2 second distance
d3 diameter, third distance
d4 diameter, fourth distance
hg height of the gasket
70 casting mould
72 mould side wall
73 mould side wall
74 first mould end part
75 apertures
76 second mould end part
78 bottom mould part
80 anti-adherent element
1. A foundation for an overhead line mast, power line mast or the like, comprising a
reinforced concrete pile including threaded bolt connectors, a number of gaskets and
a corresponding number of tightening nuts:
- said reinforced concrete pile defining an elongated structure having a first end
part including a planar abutment surface of a first polygonal geometry and a second
end part, steel reinforcement elements extending between said first end part and said
second end parts, said threaded bolt connectors being embedded in said reinforced
concrete pile and each having an exposed part extending beyond said first end part
and positioned in a second polygonal geometry and connected to said steel reinforcement
elements of said reinforced concrete pile, said second polygonal geometry being equivalent
to said first polygonal geometry,
- each of said exposed parts of said threaded bolt connectors having a first portion
including a threaded portion, a second portion having a circular cross sectional configuration
of a first outer diameter and a transition portion interconnecting said first portion
and said second portion,
- a first interface being located between said first portion and said transition portion
of each of said threaded bolt connectors at a first distance from said planar abutment
surface,
- a second interface being located between said transition portion and said second
portion of each of said threaded bolt connectors at a second distance from said planar
abutment surface, said first distance being larger than said second distance,
- each of said gaskets having an annual shape defining a second inner diameter and
second outer diameter,
- said tightening nuts having a first end surface, a second end surface and a central
aperture including a tapered portion at said second surface end for providing a larger
opening compared to said central aperture, said central aperture further including
a third internal threaded portion at said first end surface complimenting said threaded
portion of said threaded bolt connectors,
- said second inner diameter of said gasket being congruent to said first outer diameter
of each of said second portions of each of said threaded bolt connectors and said
second outer diameter being larger than said inner diameter of said third internal
threaded part of said tightening nuts,
- said tightening nuts being configured to be rotated relative to said threaded portion
of said threaded bolt connectors for allowing said gaskets to be compressed towards
said threaded bolt connectors, said tapered portion of said tightening nuts and said
planar abutment surface for providing sealing relative to said threaded bolt connectors
and said planar abutment surface.
2. A foundation according to claim 1, wherein said transition portions having threaded
portions being tapered over two revolutions from a fully threaded shaft to a plain
unthreaded shaft.
3. A foundation according to any of the preceding claims, said central aperture of said
tightening nuts having an intermediate section having a second threaded section, said
second threaded section extending between said tapered portion and said third internal
threaded portion, said second threaded section having a diameter being larger than
the thread angle of the said third internal threaded portion.
4. A foundation according to claim 1, wherein said third internal threaded portion being
tapered over two revolutions.
5. A foundation according to any of the preceding claims, wherein said second portions
of said threaded bolt connectors being plain unthreaded portions.
6. A foundation according to any of the preceding claims, wherein said reinforcement
elements including additional steel reinforcement elements extending in the circumference
of said reinforced concrete.
7. A foundation according to any of the preceding claims, wherein said reinforced concrete
pile is a prefabricated structure.
8. A foundation according to any of the preceding claims, wherein said second polygonal
geometry and said first polygonal geometry being 3-12, preferably 4.
9. A foundation according to any of the preceding claims, wherein said reinforced concrete
pile having visual markings on the outer surface for positioning said end part 0,1-1
meter above ground level, when said reinforced concrete pile is being driven into
the ground.
10. A foundation according to any of the preceding claims, wherein said threaded bolt
connectors being connected to said steel reinforcement elements of said reinforced
concrete pile by welding, preferably friction welding.
11. A method of establishing a foundation for an overhead line mast, power line mast or
the like, comprising a reinforced concrete pile including threaded bolt connectors,
a number of gaskets and a corresponding number of tightening nuts:
- providing said reinforced concrete pile defining an elongated structure having a
first end part including a planar abutment surface of a first polygonal geometry and
a second end part, steel reinforcement elements extending between said first end part
and said second end parts, said threaded bolt connectors being embedded in said reinforced
concrete pile and each having an exposed part extending beyond said first end part
and positioned in a second polygonal geometry and connected to said steel reinforcement
elements of said reinforced concrete pile, said second polygonal geometry being equivalent
to said first polygonal geometry,
- providing each of said exposed part of said threaded bolt connectors having a first
portion including a threaded portion, a second portion having a circular cross sectional
configuration of a first outer diameter and a transition portion interconnecting said
first portion and said second portion,
- providing a first interface being located between said first portion and said transition
portion of each of said threaded bolt connectors at a first distance from said planar
abutment surface,
- providing a second interface being located between said transition portion and said
second portion of each of said threaded bolt connectors at a second distance from
said planar abutment surface, said first distance being larger than said second distance,
- each of said gaskets having an annual shape forming a second inner diameter and
second outer diameter,
- providing said tightening nuts having a first end surface, a second end surface
and a central aperture including a tapered portion at said second surface end for
providing a larger opening compared to said central aperture, said central aperture
further including a third internal threaded portion at said first end surface complimenting
said threaded portion of said threaded bolt connectors,
- said second inner diameter of said gasket being congruent to said first outer diameter
of each of said second portions of each said threaded bolt connectors and said second
outer diameter being larger than the inner diameter of said third internal threaded
part of said tightening nuts,
- rotating said tightening nuts relative to said threaded portion of said threaded
bolt connectors, compressing said gaskets towards said threaded bolt connectors, said
inner tapered portion of said tightening nuts and said planar abutment surface and
establishing sealing relative to said threaded bolt connectors and said planar abutment
surface.
12. A method of establishing a foundation according to claim 11 further rotating said
tightening nuts in a predetermined tightening sequence providing a preloaded connecting
between said reinforced concrete pile and the overhead line mast, power line mast
or the like.
13. A method of establishing a foundation according to claim 11 or 12 further including
any of the features of the system according to claims 1-10.
14. A method of casting a reinforced concrete pile for a foundation, wherein said foundation
comprising a reinforced concrete pile including threaded bolt connectors, a number
of gaskets and a corresponding number of tightening nuts, said method comprising the
step of:
- providing a casting mould having two mould side walls, a first mould end part including
apertures, a second mould end part and a bottom mould part,
- inserting a number of anti-adherent elements made of a synthetic material, Teflon
or the like into the apertures of the first mould end part,
- placing steel reinforcement elements into the casting mould and said steel reinforcement
elements extending between said first end part and said second end parts of the casting
mould, a number of threaded bolt connectors being connected to said steel reinforcement
elements and allowing said threaded bolt connectors to extend beyond said first mould
end part,
- pouring concrete into the casting mould.
- casting a reinforced concrete pile defining an elongated structure having a first
end part including a planar abutment surface of a first polygonal geometry and a second
end part, steel reinforcement elements extending between said first end part and said
second end parts, said threaded bolt connectors being embedded in said reinforced
concrete pile and each having an exposed part extending beyond said first end part
and positioned in a second polygonal geometry and connected to said steel reinforcement
elements of said reinforced concrete pile, said second polygonal geometry being equivalent
to said first polygonal geometry.
15. A method of casting a reinforced concrete pile for a foundation according to claim
14, wherein said method further comprising the step of:
- arranging said threaded bolt connectors in the casting mould for providing a reinforced
concrete pile having a first interface being located between said first portion and
said transition portion of each of said threaded bolt connectors at a first distance
from said planar abutment surface, and a second interface being located between said
transition portion and said second portion of each of said threaded bolt connectors
at a second distance from said planar abutment surface, said first distance being
larger than said second distance.