GB2305948A - Ground bolts - Google Patents

Abstract

A ground bolt comprises a shaft 13, a screw member 14 fast with said shaft, a reaction member 15 and means 17 to apply a rotational torque. The screw may take the form of spiral metal flighting welded at or near the lower end of the shaft, which may be pointed 13A, and the reaction member may be a plate fast with the shaft, or a captive sliding fit thereon; the plate 15 and flighting 14 cooperate to compress the soil between them to give enhanced securement. Nut 17 may be replaced by various fitments, e. g. an upstanding screw thread or inverted U shape or pillar for the attachment of a signpost, or a hook, or several bolts may coact with one large reaction plate, which may have secured thereto a socket for a fence post. A socket spanner may be used to insert the ground bolt.

Description

IMPROVEMENTS IN OR RELATING TO GROUND BOLTS This specification relates to securing means which are screwed into the ground for the purpose of securing articles in place. Such articles may be road signs, guy lines, seats, litter bins, fencing posts, etc.

The problems of securing road signs, fencing posts against the ravages of high winds and/or vandalism are well known. The normal method (Fig. 1) of securing road signs 1 is to dig a hole in the ground 4, insert post 2 and backfill with concrete 5 and, possibly also, hardcore. The disadvantages are the time taken, physical labour involved, risk that someone may pull the sign out of position before the concrete has set and difficulty removing the sign at a future date. Another problem of such a rigid fixing is that, if a vehicle collides with it, the occupants invariably suffer more serious injuries than if the car had hit a less resilient object.

Conventional pegs 5 which are hammered into the ground are also lcnown (Fig. 2).

The action of hammering causes compression 7 of the ground 4 below the point which acts to oppose the fitting of the peg 5 and may play a small part in helping to dislodge it when subject to the effect of a lateral force 6. The small projected area of peg 5 below ground is shown hatched. When subject to a lateral force 6, peg 5 tends to pull out of the ground 4 in a pivoting form of motion with the top and bottom moving 6A and 6B respectively, as shown.

Screwed means 9 (Fig. 3) are known in which a screw 10 is fast with shaft 8. When subject to a lateral force 6, the top tends to move 6A as shown. The threads on screw 9 generate reaction forces 11 A and 1 B in the soil, as shown, in an essentially vertical plane and one effect is that the topmost threads tends to lift the soil 4A through the soil surface 3.

There is thus a need for a ground bolt that can be easily inserted into the ground, and equally easily removed, and which is more secure than pegs or conventional ground bolts.

According to a first aspect of the invention, there is provided a ground bolt comprising a shaft, a screw member fast with said shaft, a reaction member and a means to apply a rotational torque to said shaft.

According to a first variation of the first aspect of the invention, there is provided a ground bolt comprising a shaft, a screw member fast with said shaft and near to one end of said shaft, a reaction member at or near the other end of said shaft and a means at or near said other end of said shaft to apply a rotational torque to said shaft.

Preferably the shaft is sturdy and of metal construction, e.g iron or steel, and of a reasonable length and the screw member is an Archimedian Screw, or equivalent, welded to the shaft. Spiral metal strip known as 'flighting' is available and is preferred as the screw member for this application. It is preferred that the flighting is welded on to give a right hand thread. The reaction member is preferably a sturdy plate and designed to withstand a direct load at right angles to its own plane as well as bending stresses. The means to apply a rotational torque could be an hexagonal or square nut, welded axially to one end of the shaft. The screw member ideally consists of a single complete spiral attached near one end of the shaft and the means to apply rotational torque is affixed at, or near, the other end of the shaft.The reaction plate is fast with the shaft and aligned at right angles to it. Preferably the end of the shaft, adjacent to the flighting, is pointed.

According to a second variation of the first aspect of the invention, said reaction plate is provided with a hole through which said shaft passes so that said reaction plate is captive on said shaft between said screw member and said means to apply rotational torque to said shaft.

According to a third variation of the first aspect of the invention, said reaction member is fast with said shaft.

According to a fourth variation of the first aspect of the invention, downwardly pointing barbs are provided on the underside of said reaction member.

Preferably the reaction member is a circular, square or rectangular plate with a hole through it, ideally near the middle, and is fitted on to the shaft between the nut and the flighting. It may be either welded in position adjacent to the nut or allowed to float on the shaft between the screwed means and the nut. When floating reaction plates are used, barbs may be provided on the underside to engage with the ground and so stop rotation of reaction plate when the ground bolt is secure. This is advantageous if the reaction plate may be subject to lateral forces from a variety of directions which might otherwise cause it to rotate were it not so restricted.

When in use, the point of the shaft is pressed into the ground and a means of rotation, e.g. a spanner, is fitted to the nut. Gentle downward pressure is applied to the shaft via the nut while the bolt is turned using the spannner. As the flighting digs into the soil further rotation causes it to pull the bolt down into the ground until all the shaft is in the ground and the reaction plate contacts the surface of the soil. Further rotation of the nut with the spanner will tighten the bolt into the soil so that the upward force generated in the soil by the screw means acts in opposition to the downward force exerted on the soil by the reaction plate. Thus the soil between the screw means and the reaction plate is in compression and so the ground bolt is held securely.This is analogous to a wood screw in block of wood where the outward force generated by the screw threads opposes the inward force on the underside of the screw head. By locating the ground bolt so positively, it is much more secure than, for example, a conventional peg hammered into the earth, because the ground bolt exerts its retaining force on a much larger volume of soil than does the peg.

According to a fifth variation of the first aspect of the invention, said ground bolt is removable by reversing the torque on said means of applying rotational torque.

According to a sixth variation of the first aspect of the invention, locking means are applied to said means of applying rotational torque.

In many cases, a ground bolt needs to be removable, e.g. if it is used to secure a temporary sign. This is done by applying reverse torque to the nut, i.e. unscrewing it.

However, often temporary signs are subject to vandalism and conventional devices to prevent unauthorised usage are applicable.

According to a second aspect of the invention, said shaft is extended beyond said reaction member to provide an upstand.

According to a first variation of the second aspect of the invention, said upstand is adapted so that objects may be secured thereto.

Preferably the upstand is adapted to provide spaces, e.g. holes, eyes, etc., so that articles, for example, temporary road signs, etc., may be tied, clipped or otherwise secured thereto. In this case the nut is axially fast at the top of the upstand and the ground bolt is screwed into position until the reaction plate is firmly in contact with the surface of the ground, so that the upstand extends vertically above the ground. In this aspect of the invention, the reaction plate may be fast with the shaft at the base of the upstand. Alternatively, it may be loose on the shaft and bear on a bush fast with the shaft at the base of the upstand.

According to a second variation of the second aspect of the invention, said upstand is adapted so that tubular members are fittable axially thereto.

In one preferred design, the upstand is of an inverted U-shape form of an overall diameter such that standard size traffic sign poles can be slipped over the upstand and secured thereto. The U-shape is only one of a number of possible adaptations but is a convenient form to which the nut can be welded at the top.

According to a third variation of the second aspect of the invention, said upstand is threaded so that nuts and locking nuts are fittable.

In this variation, a screw thread is provided so that the ground bolt may be used to secure articles such as children's play frames, seats etc. in position. Ground bolts may be provided with standard lengths of thread and, depending on the application, the excess cut off with an hacksaw.

According to a fourth variation of the second aspect of the invention, an hook may be provided between said reaction member and said means of providing rotational torque.

According to a fifth variation of the second aspect of the invention, an hook is provided fast with said reaction member.

In this fourth variation, the hook may act vertically downwards to secure an item in position on the ground. Preferably a washer is provided between the hook and the nut and the reaction plate is floating on the shaft so that, when the bolt is tightened, the compressive forces generated will secure the hook in the desired position. In an alternative arrangement (fifth variation), the hook may be integral with the reaction plate, for example to secure a guyline, and barbs may be provided to prevent rotation of the reaction plate.

According to a sixth variation of the second aspect of the invention, members attached to said upstand are used as the means to apply said rotational torque.

In one application of the invention, a warning sign is fast with the upstand and the radial limbs of this sign can be used to provide the rotational torque to set the ground bolt in the soil and to remove, when required.

According to a third aspect of the invention, a plurality of ground bolts is used to secure a member which effectively acts as an extended reaction member for each one of said plurality of ground bolts.

The reaction member may be in the form of a plate having extended area with, for example, holes or slots therein. Ground bolts may either be provided with removable nuts so that they can be fitted through the holes and a number of ground bolts used to secure the reaction plate to the ground. Alternatively, the ground bolts may be fitted with downwardly pointing hooks; these ground bolts would be fitted adjacent to the reaction plate and the hooks engaged in the holes before final tightening.

In an alternative arrangement, the extended area reaction member may be in the form of strips or a flat framework with holes or slots provided at appropriate locations. The ground bolts may be secured through the holes or via hooks as described above. When using such extended reaction plates, upstands may be provided, e.g. to affix fencing posts, finger posts or road signs, etc.

According to a fourth aspect of the invention, said upstand on said extended reaction member is not welded round the whole of its circumference to said reaction plate.

According to a first variation of the fourth aspect of the invention, a flexible link is provided between said upstand and said reaction plate.

In this aspect of the invention, the upstand is designed to break away from the reaction plate if struck violently, for example, by a car crashing into the traffic sign post attached to the upstand. This is intended to minimise injury to the occupants of the car. The flexible link will retain the upstand and post at the scene of the accident.

Instead of a full circumferential weld around the base of the upstand to the reaction plate, the weld is preferably in interrupted portions. This gives a weaker bond than obtained with a full circumferential weld; depending on the relative lengths of welded and unwelded portions, the strength of the bond can be varied to suit any particular application.

For a clearer understanding of the invention and to show how the same may be put into effect, reference will now be made, by way of example only, to the attached drawings in which: Figure 1 is a sectional elevation of a road sign concreted into the ground. (Prior art) Figure 2 is a sectional elevation of a peg which has been hammered in to the ground.

(Prior art) Figure 3 is a sectional elevation of a screwed peg inserted into the ground. (Prior art) Figure 4 is an elevation of the ground bolt of the invention.

Figure 5 is one form of the leading edge of the flighting of the invention.

Figure 6 is a second form of the leading edge of the flighting of the invention.

Figure 7 is a sectional elevation of the apparatus of the invention shown inserted into the ground.

Figure 8 is one variation of the apparatus of the invention.

Figure 9 is a second variation of the apparatus of the invention.

Figure 10 is a third variation ofthe apparatus ofthe invention.

Figure 11 is a fourth variation of the apparatus of the invention.

Figure 12 is a perspective view of a fabricated reaction plate to fix a fence post for use with the apparatus of the invention.

Figure 13 is a plan view of one form of reaction member to fix a road sign post for use with the apparatus of the invention.

Figure 14 is a plan view of another form of reaction member to fix a road sign for use with the apparatus of the invention.

Figure 15 is an elevation of a temporary road sign adapted for use with the apparatus of the invention.

Figure 16 is a sectional elevation of the installation of the reaction member shown in Figures 14 or 15 with a road sign fitted and incorporating a crash safety device.

Figure 17 is a sectional elevation of a fifth variation of the apparatus of the invention with a removable fitting plate.

Figure 18 is a sectional elevation of a sixth variation of the apparatus of the invention with the reaction member fitted with an hook.

Figure 19 is a perspective view of a ground bolt of the invention with lateral reaction vanes fitted to the underside of the reaction plate.

Figure 20 is a side elevation of the ground bolt shown in Figure 19.

Figure 21 is a plan view of the reaction plate and vanes on the ground bolt shown in Figure 19.

In the following description, the same reference number is used for the same component or different components fulfilling identical functions..

Referring to Fig. 4, the ground bolt 12 consists of a sturdy shaft 13 pointed at its lower end 13A with a section of flighting 14 fast adjacent to the point 13A. Flighting is a continuous 'Archimedes spiral' made of a suitable material; for this application, mild or high tensile steel is preferred. The preferred method of securing the flighting 14 to shaft 13 is welding. As shown, only about one complete spiral 14 is required. The flighting may be galvanised, or given other appropriate anti-corrosion protection, if required. At the upper end, a reaction plate 15 is provided fitted normally about shaft 13. At the top of shaft 13 is a means to insert the the bolt 12 into the ground; in this case, a nut or offcut of hexagonal bar is welded axially on to shaft 13. Reaction plate 15 is shown welded to shaft 13 but this is not essential and reaction plate 15 could be a sliding fit on shaft 13 provided that it was held captive by nut 17 or by a bush (not shown) fast with shaft 13..

Fig. 7 shows how the ground bolt 12 is used. The point 1 3A is pushed 21 into the surface of ground 3. Via a spanner (not shown but indicated by line 22), a torque 23 is applied to turn nut 17 while maintaining pressure 21 on point 13A. Tests have shown that a conventional ratchet socket drive handle provides adequate torque and reasonable hand pressure 21 on the socket drive is enough to start the flighting 14 cutting into soil 4. Once flighting 14 has started to 'bite', further pressure 21 is not necessary as the spiral shape of flighting 14 draws bolt 12 into soil 4. Though a spanner is the most suitable means for the insertion of individual bolts 12, pneumatic or hydraulic means are equally possible and will be preferable when a number of bolts 12 have to be inserted.

As bolt 12 is driven home, reaction plate 15 is pressed onto the surface of ground 3 by nut 17 as the bolt 12 becomes tight. When this happens, there is a downward force 20 onto the soil from reaction plate 15 acting in opposition to an upward force 19 in the soil generated by flighting 14. The effect ofthese opposing forces is to compress soil 4A in the three dimensional diamond shape defined by lines 1 9A and 20A and so increase the volume of soil which acts to hold bolt 12 in place. In order to fit Figure 7 onto the page, reaction plate 15 and flighting 14 are shown smaller in diameter than they would be in practice and shaft 13 is equally shorter.The angles of lines 19A and 20A are typical but will depend on the nature ofthe soil structure, i.e. particle size, stone content, moisture level and cohesiveness (e.g. whether it is clay or sandy), etc.

As shown in Fig. 7, it is the bottom of the flighting 14 which defines the size of diamond 4A; several spirals of flighting 14 would superimpose smaller diamonds inside diamond 4A without adding to the volume of securing soil 4A but would increase the effort needed to insert, or remove, bolt 12. Thus only an effective single spiral of flighting 14 is used. This is an important difference over the prior art To help flighting 14 cut through soil 4, the leading edge 18 may be trimmed or faired, or left as a straight radius 1 8A, e.g. as shown in either Figs. 5 or 6. Leading edge 18 is fettled to remove any burrs and give a sharp form to cut through soil 4; where bolts 12 are intended to be removable, the trailing edge is similarly treated. By leaving the trailing edge rough, removal of bolt 12 is more difficult thus detering unauthorised activities.Special tamperproof nuts or other means, e.g. circumferential cuts in to the radial trailing edge (not shown), may also be used. Another option is to bend the trailing edge downwards so that it tends to cut back down into the soil if unscrewed.

Figs. 8 to 11 show some adaptations of the invention for specific applications. The Fig. 8 adaptation is intended for use with temporary signs, for example at road works, where the signs may have to be put up in a hurry, moved from place to place, and left in position overnight, through gales, etc. The bolt is provided with an upstand 24 to which a rod 25 is secured via rods 26 to create spaces 27 through which, for example, a cord may be passed to tie the sign to the upstand 24 of the bolt. This adaptation is designed to be removable from the ground so that it can be used repeatedly.

The Fig. 9 adaptation has either one, or two, inverted U-shaped upstands 24 so that a temporary sign, e.g. an Estate Agents' house sale sign, can be secured, e.g. via set screws, to stiffening member 28, or tied or taped into position. Member 28 stiffens upstand(s) 24 for insertion of the bolt via nut 17. In Fig. 10, the upstand 24 is threaded and a nut 17 and locknut 1 7A are provided for fitting the ground bolt initially and subsequently securing articles, such as seats, litter bins, children's climbing frames, etc.

The length of thread 24 may be reduced, where appropriate, by cutting with an hacksaw.

In Fig. 11, upstand 24 carries a washer 29 to clamp hook 30 against reaction plate 15.

Hook 30'is free to rotate about upstand 24 so that tip 30A may be inserted into a suitable hole or slot, as will be explained hereinafter. Reaction plate 15 may, or may not, welded to shaft 13 so that the compressive forces generated 19, 20 (Fig 7) will lock hook 30 in position. The end 30A of hook 30 may be longer than shown so that it engages positively with the reaction plate or object being secured in place, or digs in to ground surface 3.

Fig. 12 shows a plate 31 with a fabricated box member 33. Holes 32 in plate 31 are provided to engage with the tips 30A of hooks 30, or screwed upstands 24 (Fig. 10).

Thus, 2,3 or 4 bolts of the Fig. 10 or 11 designs are set in the ground and the fabrication of Fig. 12 secured in position. When Fig. 10 bolts are fully home, nut 17 and locknut 1 7A are removed and plate 31 fitted so that screwed upstands 24 pass through a selection of holes (or slots) 32 and a washer (not shown) and nuts 17, 17A are replaced. A fence post, or finger post, is then fitted in holder 33 and secured via screws in holes 34. If Fig. 11 bolts are used, plate 31 is placed in position and bolts (Fig. 11) loosely fitted and adjusted so that hooks 30A engage with holes 32, before final tightening.

The extended area of plate 31 acts as a large reaction plate 15 for the bolts holding it in position so that the combined effect is to give a very secure platform for the post in holder 33.

Figs. 13 and 14 show two forms 35, 36 of reaction plate 15 designed to hold a road traffic post 2. Here three arms are arranged with holes 32 near the ends of the arms to create a form of 'spider'. The tubular upstand 37 is at the point where the arms meet.

Instead of a hole, a slot 32A is shown as another means to facilitate actual placing the bolts and spider 35 or 36 in position. Equiangular spacing ofthe arms 36 (Fig. 14) is preferred to give an even support to post 2 in upstand 37, but offset arms 35 (Fig. 13) are used where the post 2 has to be located close to a wall. Fig. 16 shows the use of the spider 36 in an urban setting. The spider 36 is fitted as hereinbefore described after a thin layer of topsoil has been removed so that nuts 17 are below the required ground level. A layer of tarmac 40 is then applied to cover nuts 17 and give a smooth surface on which to walk. Ground bolts ofthe Figs. 10 or 11 designs are ideal for this application. Alternatively, holes 32 could be made large enough for flighting 14 to pass through; in this case a reaction plate 15, of larger diameter than the flighting, would be used under nut 17 to cover hole 32.

Another feature of the apparatus of the invention shown in Fig. 16 is that welding 16A is not a complete run but an intermittent one and consequently not as strong so that, if post 2 is struck by a car, it will shear off at weld 16A. This feature will lessen the likelihood of serious injury to the occupants. The intermittent nature of weld 16A is shown with welding at only one side of upstand 37. A flexible link 42 may be provided to retain upstand 37 to spider 36.

In another application (Fig. 15), the sign is integral with the upstand 24 of the bolt and the width of the sign, or its frame, is used 22 to provide the leverage to screw it into the ground. Reaction plate 15 may, or may not, be needed for this type of very short term reusable requirement and so is shown dashed.

Fig 17 shows another variation of the bolt 12 provided with a removable fitting plate 49 which engages with screws 45 via holes 50 and is held in place via nuts 46. Nut 17, welded 16 to fitting plate 49, is coaxial with shaft 13 and allows the bolt to be screwed in via holes 50, screws 45, reaction plate 15 and weld 16. Once set, fitting plate 49 is removed and an article, e.g. a litter bin, secured to screws 45.

Fig 18 shows the use of a reaction plate 15 fitted with an hook 48. Here barbs 44 are used to prevent rotation of plate 15 which is not welded to shaft 13. A washer 43 bears on plate 15 as nut 17 is tightened and drives barbs 44 into soil 4. Barbs 44 stop plate 15 from rotating, after it has been aligned and set in soil 4, so that hook 48 faces in the desired direction.

Though Fig. 16 shows a means which allows post 2 to break away from reaction plate 36, there are instances where resistance to an impact, or a steady pull, is required.

Fig. 19 shows a variation ofthe apparatus in which a removable reaction plate 51 has a number of vanes 52 fast with the underside. Here, three radial vanes are shown but any number, or arrangement, of vanes is possible. The vanes engage with the soil to provide a reaction force to resist impacts, or steady forces, on pole 2.

The upper part of shaft 13B is threaded; in fact, the whole of shaft 13 could be made of stud iron. To set the ground bolt in place, reaction plate 51 is removed and nut 17 and locknut 1 7A replaced. The ground bolt is screwed into soil 4, as hereinbefore described. Nuts 17, 1 7A are removed and plate 51 replaced. Washer 1 7B and nut 17 are replaced and vanes 52 forced into soil 4 by screwing down nut 17 on thread 1 3B against the reaction from flighting 14. In order to speed up this process, it may be convenient to place plate 51 on shaft 13 and press down, e.g. by standing on it, so that the radial positions of vanes 52 are marked on the ground 3.Spades could then be driven into the ground along these radial marks to ease the passage of vanes 52 into soil 4 (and perhaps also remove any large stones encountered). When plate 51 is at the desired depth, preferably slightly under ground surface 3, locknut 1 7A is fitted and tightened against nut 17.

Connecting piece 37 is fitted to bolts 45, which are welded to plate 51, via holes 50 and nuts 46. Post 2 may now be fitted 41 and the ground made good, e.g. by tarmacing.

Fig. 20 shows a sectional elevation of the post 2 in place. Assume a car strikes the post, as indicated by arrow 53. This will cause a clockwise turning moment 55 about some fulcrum near tip 13A. The presence of vanes 52 will act on soil 4 to produce a reaction force 54 acting about a moment 56. If the force 53 is of the order of 1.5 Te, reaction vanes having a radius of about 320mm (13 ins) and a depth of about 200mm (8 ins) will provide an adequate reaction 54. Plate 51 and vanes 52 may be made of steel or high quality polymer.

Referring to Fig. 21, the reaction force provided by the vanes 52 is shown with its resolved components. If the force is applied along line 54A, the reaction RA will be: RA=Fxd[r+ss] (1) =Fxd [r+r.sin300] = F x d [ r + r. l/2 ] =Fxl.S[dxr] (2) where F = the reaction force per unit area of soil d = the depth of vane 52 (Fig. 20) ss = the dimension shown in Fig. 21.

If the reaction force RB is along line 54B, it will have the value of: RB=Fxd[2xa] (3) - F x d [2 x r cos 300] =Fxd[2xr43/2] RB=Fx 1.732[dxr] (4) where a = the dimension shown on Fig. 21.

Ground bolts fitted with vanes 52 are ideal for such applications as fence posts, road signs in windy locations or where car impact or vandalism are expected and for crowd control barriers, etc.

Tests have shown that flighting 14 can cope with small stones but not large rocks.

This is why adaptations such as shown in Fig. 11 are disclosed so that bolt 12 can be moved to an adjacent location to avoid the rock yet still allow hook 30, 30A to engage with hole 32. Ground bolts ofthe invention may be inserted at small angles to the vertical; in such cases, it is preferable that the reaction plate is not welded to the shaft so that it can act normally on the ground surface. One particular application is to fit the bolt 12 into newly poured wet concrete and fit the article to be attached when it has set.

Many other applications of the ground bolts will be apparent to the man skilled in the art, some of which may require conventional adaptations similar to those shown in Figs 8 to 11. Possible examples are: securing guy lines for marquees, flag poles, etc., securing retaining members to banking to prevent landslips; securing seats, play frames, etc. in parks; . use on farms, in Country Parks, forested land, national parks, etc.

The dimensions of bolts 12 are chosen appropriately for each application. When used in normal soil, typical dimensions are a shaft diameter of 15-20 mm, a shaft length of 300450 mm, 100 mm wide flighting with a pitch of 50-75 mm and a reaction plate of 200-300 mm. A socket spanner handle, preferably with a ratchet is an ideal means to insert the ground bolt of the invention.

Various developments of the ground bolt will be apparent to the man skilled in the art.

In one of these, the shaft is hollow. The point would be solid but radial holes (not shown) would be provided in the general area where flighting 14 is attached. A connection (not shown) would be provided above reaction plate 15, possibly incorporating a rotary seal, to allow for a pressure to be applied and maintained in the shaft 13 as the bolt 12 is inserted into the ground 4. This would be to stop the ingress of soil into the hollow of shaft 13 which would otherwise block it. This option allows watery cement mixtures or resins to be pumped through the hollow shaft 13 into the ground which, when set, would increase the strength of the bond between bolt 12 and soil 4. This option could be of significant benefit in dry, sandy soils, where the cement or resin could percolate through a large volume of adjacent soil.

Claims (35)

What I claim is:

1. A ground bolt comprising a shaft, a screw member fast with said shaft, a reaction member and a means to apply a rotational torque to said shaft.

2. A ground bolt, as claimed in claim 1, comprising a shaft, a screw member fast with said shaft and near to one end of said shaft, a reaction member at or near the other end of said shaft and a means at or near said other end of said shaft to apply a rotational torque to said shaft.

3. A ground bolt, as claimed in claim 2, in which said reaction member is fast with said shaft.

4. A ground bolt, as claimed in claim 2, in which said reaction member is slidably mounted on said shaft between said screw member and said means to apply a rotational torque to said shaft.

5. A ground bolt, as claimed in any preceding claim, in which said screw member is an Archimedian spiral fast with said shaft.

6. A ground bolt, as claimed in claim 5, in which said Archimedian spiral has approximately one complete spiral.

7. A ground bolt, as claimed in claim 5, in which said Archimedian spiral has more than one complete spiral.

8. A ground bolt, as claimed in claims 1 - 7, in which the means to apply a rotational torque to said shaft is a nut fast axially with one end of said shaft.

9. A ground bolt, as claimed in claims 1 - 7, wherein said means to apply rotational torque to said shaft is via a member located at a radial distance from and fast with said shaft, or an upstand attached to said shaft.

10. A ground bolt, as claimed in claims 1, 2, 4-9, wherein downwardly pointing barbs are provided on the underside of said reaction member, pointing towards said screw member.

11. A ground bolt, as claimed in any preceding claim, wherein the end of said shaft adjacent to said screw member is pointed.

12. A ground bolt, as claimed in claim 11, which is removable from the ground by reversing the direction of applied torque.

13. A ground bolt, as claimed in claim 12, wherein the leading edge of said screw member is straight

14. A ground bolt, as claimed in claim 12, wherein the leading edge of said screw member is faired.

15. A ground bolt, as claimed in claims 13 and 14, wherein the leading edge of said screw member is sharpened.

16. A ground bolt, as claimed in any preceding claim, wherein said shaft is extended axially beyond said reaction member to provide an upstand.

17. A ground bolt, as claimed in claim 16, wherein said upstand is adapted so that objects may be secured thereto.

18. A ground bolt, as claimed in claim 17, wherein the means by which objects may be secured to said upstand is via holes, etc. in said upstand, or parts attached thereto.

19. A ground bolt, as claimed in claim 16, wherein said upstand is adapted so that tubular members may be axially secured thereto.

20. A ground bolt, as claimed in claim 16, wherein said upstand has a screw threaded portion so that nuts may be fitted thereto.

21. A ground bolt, as claimed in claim 16, wherein said upstand incorporates an hook.

22. A ground bolt, as claimed in claim 16, wherein said upstand carries members adapted to hold a sign.

23. A ground bolt, as claimed in any preceding claim, wherein an hook is provided fast with said reaction member.

24. A ground bolt, as claimed in any preceding claim, wherein a plurality of ground bolts are used to secure a common reaction member to the ground, said reaction member having an extended area.

25. A ground bolt, as claimed in claim 24, wherein said common reaction member is in the form of a plate having holes or slots therein through which said shafts, or upstands of said shafts, of said ground bolts are fitted.

26. A ground bolt, as claimed in claims 21 and 23, wherein said hooks on said upstands of said ground bolts are used to secure said common reaction member onto said ground.

27. A ground bolt, as claimed in claim 24, wherein said common reaction member is in the form of a flat spider having flat members bearing on said ground.

28. A ground bolt, as claimed in any of claims 24 - 27, wherein an upstand is fitted to the upper surface of said common reaction member.

29. A ground bolt, as claimed in any preceding claim, wherein the means of applying rotational torque is in the form of a member removably attachable to said reaction member.

30. A ground bolt, as claimed in any preceding claim, wherein said upstand on said reaction member or said common reaction member is only partly secured to said reaction member or said common reaction member.

31. A ground bolt, as claimed in claim 30, wherein a flexible linkage is provided between said upstand and said reaction member or said common reaction member.

32. A ground bolt, as claimed in any preceding claim, wherein additional reaction members are provided on the underside of said reaction member, said additional reaction members being aligned at right angles to said reaction member.

33. A method of securing an article to the ground consisting of placing a ground bolt into said ground and securing said article to said ground bolt, or parts attached thereto, said ground bolt comprising: i) a shaft; ii) a screw member fast with said shaft; iii) a reaction member; and iv) a means to apply a rotational torque to said shaft.

34. A method of inserting a ground bolt into the ground in which the pointed end of said ground bolt is placed into said ground and simultaneously applying an axial pressure to said means to apply rotational torque and applying a rotational torque to said shaft.

35. A ground bolt, as claimed in any preceding claim, as described in the attached description and with reference to the accompanying drawings.