FIELD OF THE INVENTION

The present invention relates to a concrete screw pile adapted for being installed in the ground for providing foundation for a construction or a like. Furthermore, the invention relates to a method of manufacturing a concrete screw pile.

BACKGROUND OF THE INVENTION

Today, when building a house or another construction, the typical way of constructing a foundation is by the method of making a direct foundation where a large hole is excavated in the ground and the hole is filled with concrete or a combination of sand and concrete.

At some construction sites, depending on the ground conditions, the holes made for the foundation may be several meters deep, meaning that the amount of soil that must be removed and the sand and concrete needed to be filled in the hole is extremely high. The preparation of a reliable and approved foundation made by the method of excavating a hole and fill it with concrete and sand is very time consuming and have a very high cost.

Some foundation is made by large foundation piles being hammered into the ground. The preparation of a reliable and approved foundation made by foundation piles is also a very time consuming process and a process that disturb the surroundings of the construction site, since the vibrations from the installation of the foundation piles is distributed over a large area, moreover this foundation method is also extremely expensive.

Hence, an improved foundation element for a construction would be advantageous, and in particular a more efficient and/or reliable foundation element for a construction would be advantageous. OBJECT OF THE INVENTION

In particular, it may be seen as an object of the present invention to provide a foundation element that solves the above mentioned problems of the prior art with expensive, time-consuming and disturbing known foundations.

It is a further object of the present invention to provide an alternative to the prior art.

SUMMARY OF THE INVENTION

Thus, the above described object and several other objects are intended to be obtained in a first aspect of the invention by providing a screw pile adapted for being installed in the ground for providing foundation for a construction or a like, said screw pile comprising :

- an elongated body, said body comprising :

- an upper part

- a middle part, and

- a lower part wherein at least one of the upper part, middle part or lower part of the elongated body comprises one or more threaded portions, and wherein at least a portion of the volume of the screw pile is concrete, said portion of concrete being 50% or more of the volume of the screw pile.

The invention is particularly, but not exclusively, advantageous for obtaining a reliable and effective screw pile.

Furthermore, the invention obtain a screw pile being very economically advantageous, since the volume is at least 50% concrete. Concrete is a very costfriendly material compared to all types of metal, which all the known screw piles are made of.

Moreover, the invention obtain a very manufacturing friendly screw pile. Concrete allows the screw pile to consist of only concrete or to consist of a combination of material, such as concrete with metal or fiber reinforcement. In the context of the invention, a "screw pile" may be understood as a screw-in piling and ground anchoring system used for (building) deep foundations. The screw piles sizes of tubular hollow sections or anchors shaft can vary. The hollow sections can have any form, such as circular, square, etc.

Also, screw piles might be referred to as screw-piles, screw piers, screw anchors, screw foundations, ground screws, helical piles, helical piers, or helical anchors.

In context of the invention, "volume" may be understood as a scalar quantity expressing the amount of three-dimensional space enclosed by a closed surface.

In the context of the invention "metal" may be seen as any suitable metal. Preferably, the metal used for reinforcement is steel, but no specific type of metal should be limiting for the scope of the invention.

Within the context of the invention "fiber" or "fibre" may be seen as any suitable fiber/fibre. Preferably, the fiber used is plastic or carbon fiber, but no specific type of fiber should be limiting for the scope of the invention.

In the context of the invention, the "construction" may be understood as anything from a building, a house, a light-weight house, a high-rise building, terraces, sheds, garages, solar plants, signs (road signs), masts, (temporary) stiffeners/supports and many other constructions.

In an embodiment of the invention, the concrete screw piles is moulded before the insertion into the ground.

The embodiment is particularly, but not exclusively, advantageous for obtaining a screw pile that is not moulded in the ground either directly or in a mould in the ground, but can be moulded before inserted into the ground in a suitable manufacturing/moulding place.

In an embodiment of the invention, the screw pile comprises reinforcement. The embodiment is particularly, but not exclusively, advantageous for obtaining a concrete screw pile having an increasing strength, especially an increased torsion strength.

In an embodiment of the invention, wherein the reinforcement is made of metal or metal alloy, and/or wherein the reinforcement is made of fiber, such as plastic fiber, carbon fiber or the like.

The embodiment is particularly, but not exclusively, advantageous for obtaining a concrete screw pile combined with material being durable inside concrete and being suitable for providing an increased strength to the concrete screw pile.

In an embodiment of the invention, wherein the reinforcement is constructed at least as one or more bars, said bars being positioned either inside the concrete or surrounding the concrete or a combination thereof.

The embodiment is particularly, but not exclusively, advantageous for obtaining reinforcement suitable for providing increased strength to a screw pile.

Furthermore, the invention is advantageous, since the shape of bars makes it easy to insert the reinforcement into the concrete or into the mould before the concrete is filled in.

In an embodiment of the invention, the reinforcement is constructed at least as one or more wires, said wires being either inside the concrete, or surrounding the concrete or a combination thereof.

The embodiment is particularly, but not exclusively, advantageous for obtaining reinforcement suitable for providing increased strength to a screw pile. Further the invention is advantageous, since wires makes it easy to insert the reinforcement into the concrete or into the mould before the concrete is filled in.

Furthermore, wires is easy to shape in a desired form, making the wires a very suitable and effective reinforcement for a screw pile. In an embodiment of the invention, the reinforcement is constructed at least as one or more spirals.

The embodiment is particularly, but not exclusively, advantageous for obtaining reinforcement suitable for providing increased strength to a screw pile. Further the invention is advantageous, since the shape of reinforcement in spirals makes it easy to insert the reinforcement into the concrete or into the mould before the concrete is filled in.

Furthermore, the shape of reinforcement in spirals provide an extremely good torsion strength to the screw pile.

The dimensions and form of the spiral can be easily varied, and a suitable spiral for a screw pile is thereby always providable.

In an embodiment of the invention, wherein the reinforcement is constructed at least as an outer layer surrounding at least a part of the screw pile, preferably surrounding the entire elongated body of the screw pile.

The embodiment is particularly, but not exclusively, advantageous for obtaining reinforcement suitable for providing increased strength to a screw pile. Further the invention is advantageous, since the reinforcement being an outer layer makes is possible and sufficient to use the outer layer as a mould or as part of a mould. Thereby potentially erasing the need of a mould for moulding the concrete screw pile, since the reinforcement can be used as mould or part of a mould it selves.

In an embodiment of the invention, the outer layer has a thickness of maximum 4 mm or less.

In an embodiment of the invention, the outer layer has a thickness of 2-20 mm, such as 4-10 mm.

The embodiment is particularly, but not exclusively, advantageous for obtaining an effective and reliable reinforcement and potential mould for the concrete screw pile. In an embodiment of the invention, at least a part of the screw pile is molded into the outer layer.

The embodiment is particularly, but not exclusively, advantageous for obtaining and effective, time-effective, economically and reliable mould for moulding the screw pile.

In an embodiment of the invention, the reinforcement is constructed at least as a coating.

The embodiment is particularly, but not exclusively, advantageous for obtaining reinforcement suitable for providing increased strength to a screw pile. Furthermore, the embodiment provides a screw pile with reinforcement, wherein the amount of reinforcement can be easily varied depending on the strengthrequirements.

In an embodiment of the invention, the reinforcement is constructed at least as an alloy.

The embodiment is particularly, but not exclusively, advantageous for obtaining reinforcement suitable for providing increased strength to a screw pile. Furthermore, the embodiment provides a screw pile with reinforcement, wherein the amount of reinforcement can be easily varied depending on the strengthrequirements.

In an embodiment of the invention, the screw pile is completely manufactured before insertion into the ground, said screw pile is preferably fabricated by molding.

The embodiment is particularly, but not exclusively, advantageous for obtaining an insertion method of the screw pile being easy to perform. Further a screw pile being completely manufactured before insertion into the ground makes is easier to test the strength parameters. In the context of the invention, "completely manufactured" may be understood as the screw pile being ready to use or ready to install, when the screw piles are out of the manufacturing/fabrication/production site. No further manufacturing steps must be done, when the screw pile is delivered to the bulding site and is to be inserted into the ground. Neither does the screw pile need any further manufacturing steps after being installed in the ground.

In an embodiment of the invention, the volume of the screw pile being in concrete is preferably between 50-100%, more preferably between 65-100%, even more preferably between 80-100%, and most preferably between 90-100%.

The embodiment is particularly, but not exclusively, advantageous for obtaining a screw pile being very economically advantageous, since the volume is at least 50% concrete. Concrete is a very cost-friendly material compared to all types of metal, which known screw pile is made of.

The more volume of concrete, the more economical and the easier production.

In an embodiment of the invention, the volume of the screw pile being in concrete is 100%.

The embodiment is particularly, but not exclusively, advantageous for obtaining a screw pile being very the most possible economically advantageous, since no other material than concrete is needed.

In an embodiment of the invention, the elongated body comprises a plurality of threaded portions distributed on one or more of the upper part, the middle part or the lower part.

The embodiment is particularly, but not exclusively, advantageous for obtaining an effective and reliable screw pile, which are easy to insert into the ground and which has a strong hold in the ground.

In the context of the invention, the threaded portions can be positioned anywhere at the elongated body. The number/amount of threaded portion can vary from zero portions to a large number of portions. The threaded portion(s) can be made of concrete, or be made from another material, such as metal or fiber.

The threaded portion can be moulded in one piece together with the moulding of the elongated body, or the threaded portions can be added after moulding the elongated body.

The form and shape of the threaded portions can be any suitable variation of a threaded portion.

In an embodiment of the invention, the top of the screw pile is provided with a top portion.

The embodiment is particularly, but not exclusively, advantageous for providing a portion of the screw pile suitable for attaching a drilling apparatus for inserting/screwing the screw pile into the ground.

The top portion can be formed in any suitable shape.

In an embodiment of the invention, the top of the screw pile is provided at least one hole, preferably two or more.

The embodiment is particularly, but not exclusively, advantageous for obtaining an "integrated top portion" being the upper-part of the elongated body, wherein the hole(s) are suitable for attaching a drilling apparatus for inserting/screwing the screw pile into the ground.

In some embodiments, the sere pile comprises an elongated shaft comprising concrete, such as more than 50% of concrete, and wherein the elongated shaft is attached to a lower part comprising a threaded portion, wherein the lower part is made of another material than concrete, such as a metal, such as steel. Especially, it is preferred that only the lower part 930 has a threaded portion.

Especially, the lower part may be formed as a shell or as a solid element, such as a metal shell or a solid metal element.

Especially, the elongated shaft may comprise at least one reinforcement element, such as a reinforcement element being made of metal or metal alloy, and/or wherein the reinforcement element is made of fiber, such as plastic fiber, carbon fiber or the like.

Especially, the elongated shaft may bave a length constituting at least 70% of a total length of the screw pile, such as at least 80%.

Especially, the screw pile may be configured for being installed into the ground by application of a vibration or hammering on an upper part of the elongated shaft to cause the threaded portion on the lower portion to screw the screw pile into the ground.

In some embodiments, the elongated shaft has at least a hollow portion. In cases where the elongated shaft is made of 80-100% concrete, such hollow portion of the elongated shaft will reduce weight of the screw pile.

Especially, a volume of a solid portion of the elongated shaft is made of at least 80% concrete.

Especially, the elongated shaft may have a through-going opening from its top to its bottom. Especially, the screw pile may comprise an elongated element, such as a metal element, such as a metal rod, arranged for insertion in the through-going opening of the elongated shaft and being arranged to engage with the lower part, so as to allow the elongated element to transfer a rotational force to the lower part to cause the threaded portion on the lower part to screw the screw pile into the ground. In this way, the lower part with the threading can be driven to screw into the ground by means of the elongated element, while the concrete of the elongated shaft is not involved in transferring any torsional force during screwing. Specifically, the elongated element may have one end shaped for engagement with the lower part in a detachable manner, so as to allow the elongated metal element to be removed from the elongated shaft after installation of the screw pile. Hereby the reused for another screw pile, and the hollow part of the elongated shaft may be filled with concrete after the elongated element has been remove, and after the screw pile has been installed. Specifically, the elongated element is a solid or hollow metal rod, such as a solid or hollow steel rod. The elongated shaft may have a the same cross section from its to to its bottom, where it is attached to the lower part. However, if preferred the cross section may vary along its length. The elongated shaft may have a circular cross section. However, the elongated shaft may have other cross sectional shapes, if preferred.

In some embodiments, the elongated body has a diameter of less than 200 mm, such as less than 150 mm, such as less than 100 mm, such as less than 80 mm, such as less than 50 mm.

In some embodiments, the elongated body has a diameter of at least 20 mm, such as at least 30 mm, such as at least 50 mm, such as at least 100 mm, such as at least 150 mm, such as at least 200 mm.

In some embodiments, the elongated body has a diameter of at least 100 mm, such as at least 120 mm, such as at least 150 mm, such as at least 200 mm, such as at least 300 mm, such as at least 400 mm.

In some embodiments, the elongated body has a diameter of 100-600 mm, such as 150-500 mm, such as 200-500 mm.

In some embodiments, the elongated body has a diameter of at least 400 mm, such as at least 500 mm, such as at least 800 mm, such as at least 1000 mm.

In some embodiments, the elongated body has a diameter of 100-1000 mm, such as 200-1000 mm, such as 400-1000 mm.

The invention further relates to second aspect, providing a method of manufacturing a screw pile, the screw pile preferably being according to the first aspect, said method comprising at least the steps of:

- providing a mold,

- providing a wet concrete mixture in a liquid form,

- optionally, providing reinforcement, preferably being bars, wires or spirals,

- optionally, inserting the reinforcement into the concrete mixture,

- filling the mold with the concrete mixture, wherein said mold is completely removed after molding, or wherein the mold is an integrated part of the screw pile, such as an outer layer, not being removed after molding.

This aspect of the invention is particularly, but not exclusively, advantageous in obtaining a moulding method being very easy, economically and cost-effective to perform, while providing an effective and reliable screw pile.

The invention provides in a third aspect, a method for installing a screw pile according to the first aspect into the ground.

Especially, the method may comprise applying a rotational force on the screw pile to cause the screw pile to be screwed into the ground. Additionally, or alternatively, the method may comprise applying a vibration and/or a hammering on the screw pile during installation into the ground.

Especially, the method may comprise installing a screw pile comprising inserting an elongated element into a thorough-going opening, such as a central bore, of a screw pile with an elongated shaft made of more than 50% concrete. Next, bringing the elongated element into engagement with a threaded lower part of the screw pile made of a metal. Next, applying a torsion and/or torque to the elongated element to screw the screw pile into the ground.

The first, second and third aspect of the present invention may each be combined with any of the other aspects. These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

BRIEF DESCRIPTION OF THE FIGURES

The concrete screw pile according to the invention will now be described in more detail with regard to the accompanying figures. The figures show one way of implementing the present invention and is not to be construed as being limiting to other possible embodiments falling within the scope of the attached claim set.

FIG. 1 illustrates a screw pile with a spiral reinforcement. FIG. 2a-c illustrates a screw pile with different distributions of threaded portions. FIG. 3 illustrates a screw pile with an outer layer of reinforcement.

FIG. 4 illustrates a screw pile with bars of reinforcement.

FIG. 5 illustrates a screw pile with an outer layer of reinforcement.

FIG. 6 illustrates a concrete screw pile with no reinforcement.

FIG. 7 illustrates different types of screw pile.

FIG. 8a-c illustrate moulds for the manufacturing of the concrete screw piles. FIG. 9a, 9b illustrates embodiment with combined concrete and metal screw.

DETAILED DESCRIPTION OF AN EMBODIMENT

FIG. 1 illustrates a screw pile 100 with a spiral (530) reinforcement (500).

The screw pile illustrated in FIG. 1 is adapted for being installed in the ground for providing foundation for a construction 800 or a like, said screw pile comprising:

- an elongated body 200, said body comprising:

- an upper part 210

- a middle part 220, and

- a lower part 230 wherein at least one of the upper part, middle part or lower part of the elongated body comprises one or more threaded portions 300. In FIG. all of the upper part, middle part or lower part comprises threaded portion, however it should be understood that this illustration of threaded portions and the position and distribution of the threaded portion is not limiting to the invention. The threaded portion 300 can be positioned anywhere at the elongated body 200 (See FIG. 2a- c).

The screw pile 100 illustrated in FIG. 1 has at least a portion of the volume of the screw pile being concrete 400, said portion of concrete being 50% or more of the volume of the screw pile. The concrete screw pile according to the invention, can have a volume of the screw pile being in concrete between 50-100%, more preferably between 65-100%, even more preferably between 80-100%, and most preferably between 90-100%.

Furthermore, the concrete screw pile 100 illustrated in FIG. 1 comprises reinforcement 500. The reinforcement being shaped as a spiral 530 positioned inside the concrete and extends from the top of the upper part 210 of the elongated body 200 to the bottom of the lower part 230 elongated body. However, the extension illustrated should not be seen as limiting to the invention, since the reinforcement spiral 530 could extend from the middle part 220 to the bottom of the lower part 230, from the middle part 220 to the top of the upper part 210, only be in the middle part 220, or only in the top part 210, or only in the bottom part, or in any suitable extension of the elongated body.

Also, the spiral 530 is in FIG. 1 illustrated as being positioned inside the concrete 400 of the screw pile, however the spiral could also within the invention be positioned outside the concrete so that the spiral surrounds the elongated body 200 (not illustrated in FIG. 1).

Moreover, there could be more than one spiral 530 used for reinforcement 500, and also different shapes of reinforcement could be used, such as a combination of a spiral 530 and reinforcement bars 510, wires 520, an outer layer 540, a coating 550 and/or an alloy 560 (not illustrated in FIG. 1).

The reinforcement spiral illustrated in FIG. 1 could be made of metal, such as steel, or the reinforcement spiral could be made of fiber, such as plastic fiber, carbon fiber or the like.

The screw pile 100 illustrated in FIG. 1 is preferably manufactured by a method comprising at least the steps of:

- providing a mold 600,

- providing a wet concrete mixture 700 in a liquid form,

- optionally, providing reinforcement 500, preferably being bars 510, wires 520 or spirals 530,

- optionally, inserting the reinforcement 500 into the concrete mixture 700,

- filling the mold 600 with the concrete mixture 700, wherein said mold 600 is completely removed after molding, or wherein the mold 600 is an integrated part of the screw pile 100, such as an outer layer 540', not being removed after molding.

FIG. 2a-c illustrates a screw pile 100 with different distributions of threaded portions 300.

The position and distribution of the threaded portion 300 is not limiting to the invention. The threaded portion can be positioned anywhere at the elongated body 200.

FIG 2a illustrated the threaded portions 300 of the elongated body 200 being positioned only at the lower part 230 of the elongated body 200.

FIG 2b illustrated the threaded portions 300 of the elongated body 200 being positioned only at the lower part 230 and the middle part 220 of the elongated body.

FIG 2c illustrated the threaded portions of the elongated body 200 being positioned only at the lower part 230 and the top part 210 of the elongated body.

FIG. 3 illustrates a cross-section of a screw pile 100 with an outer layer 540 of reinforcement 500.

The concrete screw pile illustrated in FIG. 3 comprises a reinforcement 500 being constructed as an outer layer 540 surrounding the entire elongated body 200 of the screw pile. However is should be understood that the invention should not be limited to the outer layer 540 surrounding the entire elongated body, since only a part of the elongated body 200 of screw pile 100 could be surrounded of an outer reinforcement layer 540.

The outer layer 540 could have any suitable thickness. Though, the preferable thickness of the layer is maximum 4 mm or less.

The screw pile 100 illustrated in FIG. 3 is preferably molded directly into the outer layer 540' (not illustrated).

The threaded portions 300 illustrated in FIG. 3 are not encased in an outer layer 540, and is combined with the screw pile 100 after the moulding. The threaded portion could within the invention also be encased by an outer reinforcement layer 540, and could be molded together with the rest of the screw pile or be molded separately.

FIG. 4 illustrates a screw pile with bars of reinforcement. In FIG. 4 a screw pile 100 is illustrated, wherein the reinforcement 500 is constructed at least as one or more bars 510, said bars being positioned either inside the concrete 400, as illustrated, or surrounding the concrete (not illustrated) or a combination thereof. Furthermore, the bars of reinforcement can be combined with any outer kind of reinceforement (not illustrated).

FIG. 5 illustrates a screw pile with an outer layer of reinforcement. In FIG. 5 a screw pile 100 is illustrated, wherein the reinforcement 500 is constructed at least as an outer layer of reinforcement 540, said outer layer is sourrounding the concrete 400. In FIG 5, the outer layer surrounds the entire length the concrete pile, however in some emboiduments the outerlayer can sourround only parts of the length. In FIG. 5 the thinkness of the outer reinforcement layer should be understood as illustrative, within the invention the thikness of the outer layer reinceforment would be much thinner than the illustrated thikness in FIG. 5, such as 4 mm or preferably less.

Furthermore, the outerlayer reinforcement can be combined with any outer kind of reinceforement (not illustrated).

FIG. 6 illustrates a screw pile with no reinforcement.

In FIG. 6 a screw pile 100 is illustrated, wherein the volume of concrete 400 is 100%, meaning that there is no need of any combination of other material, such as reinforcement 500 in metal or fiber.

FIG. 7 illustrates different types of screw pile.

A screw pile may within the invention be understood as a plurality of numbers of different kind and models of screw piles 100. The screw piles sizes will vary. Some screw piles might be made as helix screw piles and other as ground screw pile, and some might be formed differently from any of the screw piles illustrated in FIG. 2.

Furthermore, a top portion 240 of a screw pile is illustrated. The top portion might be used to assist in screwing down the pile into the ground as the drilling apparatus might be attached to the top portion. However, the illustrated top portion 240 in FIG. 7 should not be understood as a necessity for the concrete screw 100 pile of the invention.

Screw pile parameters may within the invention be: diameter, length, thickness, weight, surface thread pitch, number of threads, thread thickness, size and/or diameter of threads.

FIG. 8a-c illustrate molds 600 for the manufacturing of the concrete screw piles. The mold can be made of any suitable material, however the mold 600 illustrated in FIG. 8a is made of Expanded polystyrene (EPS).

FIG. 8b illustrates yet another mold 600 for manufacturing the concrete screw pile, wherein the concrete 400 is not yet filled into the mold.

FIG. 8c illustrates a mold 400, wherein the concrete screw pile has been manufactured/fabricated therein.

It should be understood that the illustrated molds in FIG. 8a-c is only a half part of a mold 600. When molding the concrete screw piles two of the illustrated parts of the molds 600 are combined into on closed mold suitable for filling in concrete 400 (and optionally reinforcement 500) and forming a concrete screw pile 100 according to the invention.

The method of manufacturing a screw pile 100 in the mold comprises at least the steps of (not illustrated):

- Providing a mold 600,

- Providing a wet concrete mixture 700 in a liquid form,

- optionally, providing reinforcement 500, preferably being bars 510, wires 520 or spirals 530,

- optionally, inserting the reinforcement 500 into the concrete mixture 700,

- filling the mold 600 with the concrete mixture 700, wherein said mold is completely removed after molding, or wherein the mold is an integrated part of the screw pile 100, such as an outer layer (540'), not being removed after molding, and where in the steps of the method can be performed in any order, subsequently and/or simultaneously. FIG. 9a and 9b illustrate two screw pile embodiment with an elongated shaft 910 made of concrete, or at least more than 50% or concrete, wherein the elongated shaft 910 is attached to a lower part 930 which is made of another material than concrete, preferably a metal such as steel. Only this lower part 930 has a threading so allow the screw pile to be screwed into the ground.

In FIG. 9a the elongated shaft can be made of 80-100% concrete, e.g. concrete comprising at least one reinforcing element, such as metallic reinforcing elements or the like as already described for embodiments in the foregoing.

Since only the lower part 930 is threaded, the screw pile of FIG. 9a may be arranged to be screwed into the ground by applying a longitudinal vibration or hammering onto the elongated shaft 910, which then causes the lower part 930 to screw the screw pile into the ground due to its threading.

The lower part 930 is preferably formed as a metal shell or a solid metal element, such as a steel shell or a steel element, so as to provide a tortional strength which is superior to the torsional strength of the elongated concrete shaft 910. This allows a rather thin elongated concrete shaft 910 to provide the necessary strength for the screwing process, since only a longitudinal vibration or hammering force on this part is necessary for the screwing process.

The elongated shaft 910 may have a hollow portion which saves weight of the screw pile.

FIG. 9b illustrates an embodiment, where the elongated shaft 910 made of at least 50% concrete has a through-going opening from its top to its bottom, and where an elongated element 940, preferably a metal element, such as a metal rod, can be inserted so as to engate with the lower part 930, e.g. in a detachable manner. In this way, the elongated element 940 can be used to transfer a rotational force to the lower part 930 and thereby cause the threaded portion on lower part 930 to screw the screw pile into the ground. Thus, the hollow elongated shaft 910 made of concrete is not used to transfer torsion for screwing the threaded lower part 930 into the ground. In versions where the elongated element 940 can be dismantled from the lower part 930 after the screw pile has been installed, the hollow part of the elongated shaft 910 can be filled with concrete, if preferred.

The elongated element 940 can be a solid or a hollow metal rod, such as a solid or hollow steel rod. Especially, it may be preferred that the elongated element 940 has one end shaped for engagement with a portion of the lower part 930 to allow transfer of a torsional force to the lower part 930 while at the same time allow disengagement from the lower part 930, to allow the elongated element 940 to be removed from the hollow part of the elongated shaft 910.

Although the present invention has been described in connection with the specified embodiments, it should not be construed as being in any way limited to the presented examples. The scope of the present invention is set out by the accompanying claim set. In the context of the claims, the terms "comprising" or "comprises" do not exclude other possible elements or steps. Also, the mentioning of references such as "a" or "an" etc. should not be construed as excluding a plurality. The use of reference signs in the claims with respect to elements indicated in the figures shall also not be construed as limiting the scope of the invention. Furthermore, individual features mentioned in different claims, may possibly be advantageously combined, and the mentioning of these features in different claims does not exclude that a combination of features is not possible and advantageous.

REFERENCE LIST

Screw pile (100)

Elongated body (200)

- upper part (210)

- middle part (220), and

- lower part (230)

- top portion (240) Threaded portions (300) Concrete (400) Reinforcement (500) - Bars (510)

- Wires (520)

- Spirals (530)

- Outer layer (540) - Outer layer mold (540')

- Coating (550)

- Alloy (560)

Mold (600)

Wet concrete mixture (700) Construction (800)

Elongated shaft (910)

Lower part (930)

Elongated element (940)