GB2462090A

GB2462090A - A mast foundation with a plate and rods around a tube.

Info

Publication number: GB2462090A
Application number: GB0813405A
Authority: GB
Inventors: Ivan Brocklehurst; Louis Lehenaff
Original assignee: Hutchinson Engineering Ltd
Current assignee: Hutchinson Engineering Ltd
Priority date: 2008-07-22
Filing date: 2008-07-22
Publication date: 2010-01-27
Anticipated expiration: 2028-07-22
Also published as: GB2462090B; GB0813405D0

Abstract

A foundation 100 for a mast or the like (134, fig 8) having a plate 102 to which the mast or the like is attachable, a tube 110 and rods 114 arranged around the tube and connected to the tube and the plate. Preferably the tube is cylindrical and the plate circular or rectangular. The plate may have holes 104A to attach the mast's plate or the like with bolts or the like. The tube is ideally central to the plate and extends through it. The tube possibly has holes 112 in its side. Reinforcing fins 120 may be between the rods and the tube and/or outward of the rods 122. Each rod may be connected to the tube by spacer rods 116 and/or a fin 118. The rods can be lengthened, preferably by tying other rods (124, fig 8) to the ends. A method of installation is also claimed.

Description

Title: Support structures

Description

This invention concerns support structures, especially for masts and the like, such as for wind turbines.

Support structures for masts and the like are buried in concrete in the ground and the mast is usually bolted to the support structure. The support structure and the mast have plates that are bolted together. Two types of support structure installation are generally used. These are so-called pad and root installations.

Referring to Figure 1 of the accompanying drawings, there is illustrated the so-called pad installation of a support structure 10 for a mast or the like. The pad installation system is generally used when it is not possible or necessary to dig a hole S..

to any great depth to receive a support structure to be concreted in place. The support 0e structure 10 comprises a temporary template 12 of any desired shape but typically ** .*

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circular or rectangular having a series of holes 14 near its edge to receive bolts 16.

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The bolts extend into the concrete to tie the support structure into the concrete.

Secondly the bolts give attachment locations for a plate 18 of a mast or like structure to be attached.

To install such a support structure, a hole is dug to a required area and depth, * the former typically being from 4 to 25m2, the support structure suspended in the hole and concrete 22 poured in to fill the hole. The means of suspending the support structure is then removed when the concrete has set and the mast or the like is then attached to the support structure.

A more cost effective and preferred alternative to the pad installation system is the so-called root installation system.

Such a prior art system is illustrated in Figure 2 of the accompanying drawings. In this system a narrower deeper hole is dug or augured compared to the pad installation system. The support structure 30 used here has a plate 32 of any suitable shape, typically round or rectangular, with a cylinder 34 depending from its intended underside. Fins 36 are welded between the cylinder and the plate for strength. Additionally a series of reinforcing rods 38 are positioned around the cylinder and these extend beyond the bottom end of the cylinder to give continuity of strength to the support structure when concreted in position.

The root support structure is concreted in a narrower but deeper hole than the pad, typically of 1m2. A plate 40 of a mast or like structure 42 is then attached to the c.

plate of the support structure using bolts as shown through aligned holes of the * * respective plates of the support structure and the mast or the like. *

A problem with the use of these support structures is that it is not always ****

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* evident as to which one is appropriate to use. For example, it may be desirable to use a root support structure but when work begins on site, it may become apparent that the depth needed for a root support structure may not be achievable because of the nature of the ground being dug, such as a rock layer near the surface. In such circumstances the job has to wait until an appropriate pad type support structure can be manufactured and delivered to site. Conversely, when a pad support structure has been chosen but the ground being dug proves to be unsuitable, so that a root installation is preferred, there is a delay while root support structure is obtained.

An object of the invention is to provide a support structure for a mast or the like that is generally versatile.

According to a first aspect of the invention there is provided a support structure for a mast or the like having a plate to which the mast or the like is attachable, a support substructure comprising a tubular member and rods arranged radially around the cylinder and connected to the cylinder and the plate.

According to a second aspect of the invention there is provided a method of providing a support for a mast or the like comprising the steps of excavating a hole, suspending a support structure in the hole and pouring concrete into the hole to secure the support structure in the hole, wherein the support structure has a plate to which the mast or the like is attachable, a support substructure comprising a tubular member and S rods arranged radially around the cylinder and connected to the cylinder and the plate. * * 555

According to a third aspect of the invention there is provided a method of

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installing a mast or the like comprising the steps of attaching the mast or the like to a *,* support structure provided by a method comprising the steps of excavating a hole, *.

suspending a support structure in the hole and pouring concrete into the hole to secure I. ** the support structure in the hole, wherein the support structure has a plate to which the mast or the like is attachable, a support substructure comprising a tubular member and rods arranged radially around the cylinder and connected to the cylinder and the plate.

The tubular member of the support structure is preferably a cylinder but may be of any other suitable cross-sectional shape.

The plate of the support structure may be of any shape but will typically be circular or rectangular.

The plate preferably has a series of holes for attachment of a plate or the like of a superstructure by means of bolts or other suitable fastening means.

The tubular member is preferably generally central of the plate and preferably extends slightly through the plate. The tubular member preferably has one or more holes in its side.

The rods of the support structure are preferably connected to the tubular member by spacer rods extending radially from the wall of the tubular member.

Additionally, reinforcing fins are preferably provided between the rods and the plate.

Preferably each rod has a reinforcing fin extending inwardly. Additional reinforcing fins may be provided extending outwardly from one or more of the rods. The rods are preferably welded into holes in the plate.

Where necessary it is envisaged that the rods may be extended by addition of **�*.

further rods, such as by tying the additional rods to the ends of the rods of the support *. structure. Such additional rods may be required to provide greater strength in depth.

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In use it is intended that the support structure of the invention will be cast into * concrete in a prepared hole and then a mast or the like attached thereto by bolts or the like once the concrete has set sufficiently.

This invention will now be further described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a first prior art support structure; Figure 2 shows a second prior art support structure; Figure 3 is a perspective view from below of a support structure according to the invention; Figure 4 is a perspective view from above of the support structure of Figure 3; Figure 5 is a first side view of the support structure of Figure 3; Figure 6 is a second side view of the support structure of Figure 3 at 900 to the first side view; Figures 7 and 8 are plan and section views respectively of root installation of the support structure of Figure 3; and Figures 9 and 10 are plan and section views of pad installation of the support structure of Figure 3.

The prior art support structure systems have been described above with reference to Figures 1 and 2 of the accompanying drawings. Turning to Figures 3 to 6 of the drawings a support structure 100 for a mast or the like, such as for a wind turbine, fabricated from steel is shown. The support structure 100 has a rectangular plate 102 shown with a circular arrangement of holes 104 and two rectangular * arrangements of holes 106. The circular arrangement of holes is for two purposes.

Every other hole 1 04A is for the fitting of bolts to secure a mast structure to the plate S..

and the alternate holes 1 04B are to receive elements of a substructure to be described *sS* below. Furthermore, the arrangements of holes 104A and 106 are illustrative only, being for a particular mast structure to be supported. The shape of the plate 102 and the arrangement of holes will be decided on the basis of the structure to be supported.

The plate 102 has a larger hole 108 near its centre through which a cylinder is welded with its intended top end protruding slightly. The cylinder wall has holes 112 radially spaced at 900 intervals.

Around the cylinder 110 are rods 114 parallel thereto. These rods are welded at their top ends into the holes I 04B of the plate and to fins 118 extending inwardly and welded to central cylinder and the underside of the plate. The rods 114 are further supported by rods 116 radially extending from the base of the cylinder 110 and welded to the cylinder and the rods.

Some of the rods have outwardly extending fins 120, 122 for additional strength for the support structure. As shown two adjacent rods have outwardly extending supporting fins 120 as well as two non-adjacent rods (fins 122) on the opposite side of the cylinder. These fins extend near to the edges of the plate. The various fins help to transfer load into the reinforcing bars.

Use of the support structure of Figures 3 to 6 is shown in Figures 7 and 8 in a root installation and in Figures 9 and 10 in a pad installation. In general a hole is dug to a required size to receive the support structure 100. For the root installation usually the first 0.5m is dug out and then the remainder of the hole is created using an auger *l.. * or a mechanically operated bucket. After the first 0.5m a 3m deep hole will usually be * about I m. The support structure 100 then has reinforcing rods 124 tied to the rods 114 of the support structure to extend to a desired depth to achieve the required bending resistance of the root. The support structure is then suspended in position in * the hole and concrete 130 poured into the hole. Bolts 132 for the attachment of a mast or like structure 134 are already in place in the holes I 04A. The concrete can be poured through the cylinder 110 as well around the plate upto the level of the plate.

Around the plate can be backfilled with material 138 previously excavated or with gravel! small stones for better drainage. The combination of the cylinder and the extended rods are bound into the concrete to provide a stable support structure for a mast or the like to be bolted to the plate.

A pad installation (Figures 9 and 10) is carried out using a support structure in a similar manner except that the hole is dug wider and to a lesser depth and no extension rods are used.

Whilst a specific form of support structure has been illustrated with reference to the drawings, it will be appreciated that size and shape parameters of the components thereof may be varied without departing from the scope of the invention. e

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Claims

Claims: I. A support structure for a mast or the like having a plate to which the mast or the like is attachable, a support substructure comprising a tubular member and rods arranged radially around the cylinder and connected to the cylinder and the plate.
2. A support structure as claimed in claim I, wherein the tubular member is a cylinder.
3. A support structure as claimed in claim I or 2, wherein the plate is circular or rectangular.
4. A support structure as claimed in claim 1, 2 or 3, wherein the plate has a series of holes for attachment of a plate or the like of a superstructure by means of bolts orSother suitable fastening means. ** *.j.
5. A support structure as claimed in any one of claims I to 4, wherein the-S 1 ** * tubular member is generally central of the plate. S.S
6. A support structure as claimed in claim 5, wherein the tubular member extends 5*5S **I*slightly through the plate. * S S.
7. A support structure as claimed in any one of claims 1 to 6, wherein the tubular member has one or more holes in its side.
8. A support structure as claimed in any one of claims I to 7, wherein the rods are connected to the tubular member by spacer rods extending radially from the wall of the tubular member.
9. A support structure as claimed in any one of claims I to 8, wherein reinforcing fins are provided between the rods and the plate.S
10. A support structure as claimed in any one of claims I to 9, wherein each rod has a reinforcing fin extending inwardly.
11. A support structure as claimed in any one of claims 1 to 10, wherein additional reinforcing fins are provided extending outwardly from one or more of the rods.
12. A support structure as claimed in any one of claims I to 11, wherein the rods are extended by addition of further rods.
13. A support structure as claimed in claim 12, wherein the additional rods are tied to the ends of the rods of the support structure.
14. A method of providing a support for a mast or the like comprising the steps of excavating a hole, suspending a support structure as claimed in any one of claims I to 13 in the hole and pouring concrete into the hole to secure the support structure in the hole.
15. A method of installing a mast or the like comprising the steps of attaching the mast or the like to a support structure provided by the method as claimed in claim 14.
16. A support structure for a mast or the like substantially as hereinbefore described with reference to and as illustrated in any one of Figures 3 to 11 of the :.:: accompanying drawings.
17. A method as claimed in claim 14 and substantially as hereinbefore described * * * *:. with reference to any one of Figures 3 to 11 of the accompanying drawings.
18. A method as claimed in claim 15 and substantially as hereinbefore described with reference to any one of Figures 3 to 11 of the accompanying drawings.