GB2511575A

GB2511575A - Ground anchor apparatus

Info

Publication number: GB2511575A
Application number: GB201304262A
Authority: GB
Inventors: Charles Simon James Agg; Michael Hamilton Russell
Original assignee: Platipus Anchors Holdings Ltd
Current assignee: Platipus Anchors Holdings Ltd
Priority date: 2013-03-08
Filing date: 2013-03-08
Publication date: 2014-09-10
Also published as: WO2014135889A1; GB201304262D0

Abstract

A ground anchor apparatus comprising a ground anchor 10 and a driving rod (90, figure 28) locatable in a socket provided in the anchor. There is a strap 40 securable at one end to the anchor, there is a strap ratchet provided by a set of teeth and a cap 70 having a slot through which the strap can be inserted. The cap has a cap ratchet (43, figure 10) provided by at least one cap tooth. The ground anchor can be driven to a desired depth in ground by application of force to the driving rod (90, figure 28) when located in the socket. The strap secured to the ground anchor can be dragged into the ground as the ground anchor is driven to the desired depth, with a second end of the strap left above ground level. The second end of the strap can be inserted through the slot in the cap with the cap ratchet engaging the strap ratchet.

Description

GROUND ANCHOR APPARATUS

The present invention relates to ground anchor apparatus and a method of use of ground anchor apparatus.

Ground anchor apparatus has been described in, for instance, GB 2283511 and GB 2283512. The apparatus comprises a metal ground anchor which is driven into the ground using a drive rod which is fitted into a socket of the ground anchor whilst the ground anchor is being driven into the ground. A percussive force is applied to the drive rod either manually, e.g. by using a hammer, or by a hydraulic or pneumatic hammer. A metal tendon is attached to the ground anchor and pulled down into the ground by the ground anchor as it is driven into the soil. Once the ground anchor has been driven to a desired depth then the drive rod is withdrawn from the socket in the ground anchor and withdrawn from the ground. Then a tensile force is applied to the anchor to rotate the ground anchor in the earth by approximately 9Y so that a load reacting surface of the earth anchor lies in a plane approximately perpendicular to an axis of the tendon; this is termed a "load locked" condition by the applicant. The tendon is then used to e.g. secure geotextile matting in place, to secure a rootball of a tree or as a guy rope to support a structure.

The ground anchors of the prior art are supplied in various sizes to support loadings of 100kg to 30,000kg. They have been very successful and are widely used. The applicant has perceived that the smaller of the ground anchors, which can support loads of 100kg, have sometimes been used to tie down ground sheets used e.g. to cover landfill sites or as the flooring of temporary structures such as field hospitals. In prior applications they are used in place of pegs which have previously been used, but which are often unsuitable since the pegs have a tendency to lift out of the ground over time, e.g. if a gust of wind lifts an edge of a pegged ground sheet.

Whilst the small ground anchors of the prior art solve the technical problems with the traditional ground pegs, they are an expensive solution, e.g. a small ground anchor of the prior art when supplied with a wire tendon will oost $10 compared with pegs which can be purchased as cheaply as $100 for 5,000. Also the installation of a ground anchor is a longer and more involved process than the driving of a peg into the ground. Thus there is a need for an inexpensive ground anchor apparatus for reacting loads of 60-65kg and suitable for use in place of pegs.

The present invention provides ground anchor apparatus as claimed in claim 1.

The present invention also provides ground anchor apparatus as claimed in claim 2.

The present invention further provides a method of use of ground anchor apparatus as claimed in claim 7.

The present Invention additionally provides a method of use of ground anchor apparatus as claimed in claim 8.

A preferred embodiment of ground anchor apparatus according to the present invention wili now be described with reference to the accompanying drawings, in which: Figure 1 is a bottom plan view of a ground anchor of ground anchor apparatus of the preferred embodiment of the invention; Figure 2 is a side elevation view of the ground anchor of Figures 1 and 3 to 8; Figure 3 is a cross-section through the ground anchor of Figures 1, 2 and 4 to 8, taken along the line A-A shown in Figure 4; Figure 4 is a top plan view of the ground anchor of Figures 1 to 3 and 5 to 8; Figure 5 is a front elevation view of the ground anchor of Figures 1 to 4 and 6 to 8; Figure 6 is a rear elevation view of the ground anchor of Figures 1 to 5 and 7 to 8; Figure 7 is a cross-section through the ground anchor of Figures 1 to 6 and 8, taken aiong the iine B-B shown in Figure 4; Figure 8 is a cross-section through the ground anchor of Figures 1 to 7, taken along the line C-C shown in Figure 4; Figure 9 is a cross-section view of a strap of a ground anchor apparatus of the preferred embodiment of the invention, taken along the line D-D of Figure 10; Figure 10 is a top plan view of the strap of Figure 9; Figure 11 is a oross-section view of the strap of Figures 9 and 10, taken along the line E-E of Figure 10; Figure 12 is a cross-section view of a lead end part of the strap of Figures 9 to 11, taken along the line F-F of Figure 13; Figure 13 is a top plan view of the lead end part of Figure 12; Figure 14 is a cross-section view of the lead end part of Figures 12 and 13 taken along the line C-C of Figure 13; Figure 15 is a detail view of a ratchet section of the strap of figures 9 to 11; Figure 16 is a cross-section view of a pivot end part of the strap of Figures 9 to 11, taken along the line H-H of Figure 17; Figure 17 is a top plan view of the pivot end part of Figures 16, 18 and 19; Figure 18 is a cross-section view of the pivot end part of Figures 16, 17 and 19, taken along the line I-I of Figure 17; Figure 19 is a cross-section view of the pivot end part of Figures 16 to 18, taken along the line J-J of Figure 17; Figure 20 is a bottom plan view of a cap of the preferred embodiment of the present invention; Figure 21 is a cross-section view of the cap of Figure 20, taken along the line K-K in Figure 20; Figure 22 is a top plan view of the cap of Figures 20 and 21; Figure 23 is a detail view of a part of the cap and is an enlarged view of a section of the bottom plan view of Figure 20; Figure 24 is a cross-section view of the cap part of Figure 23, taken along the line L-L of Figure 23; Figure 25 is a cross-section of the cap part of the Figures 23 and 24, taken along the line M-M of Figure 24; Figure 26 is a detail view of a ratchet of the cap part of Figures 24 and 25 and is an enlarged view of a portion of the cross-section view of Figure 24; Figure 27 is a schematic view showing the ground anchor of Figures 1 to 8 with the strap of Figures 9 to 19 attached thereto; Figure 28 is a schematic view showing a first step of a preferred installation method of the present invention, comprising the driving into the ground of a ground anchor of Figures 1 to 8 with the strap of Figures 9 to U attached thereto; Figure 29 shows a second step of the preferred instaliation method of the present invention, with the ground anchor of Figure 28 rotated to a "load iocked" position in the ground and the strap extending above ground level; Figure 30 shows a third step of the preferred installation method of the present invention, with the cap of Figures 20 to 21 anchored by the ground anchor of Figures 1 to 8 and the strap of Figures 9 to 19 and holding down a ground sheet; Figure 31 shows an arrangement of two of the straps of Figures 9 to 19 secured together; and Figure 32 is a similar view to Figure 30, but with the cap of Figures 20 to 26 anchored by the ground anchor of Figures 1 to 8 and by an arrangement of two straps as illustrated in Figure 31.

Figure 1 shows a ground anchcr 10 which has a driving edge 11 a rearward pivot edge 12 and an underside surface 13 which is continuously curved, in a convex fashion, from a first side edge 14 of the ground anchor 10 to a second side edge 15 of the ground anchor 10. The continuously curved arcuate surface 13 can be seen clearly in Figures 5, 6, 7 and 8.

The ground anchor has a nose seotion 16 whioh extends from the driving edge 11 to the arcuate underside surface 13.

Nose section 16 comprises a pair of concave surfaces 17 and 18, seen also in Figures 2 and 5, which are separated by a central rib 19, again seen also in Figure 5. The width of the ground anchor 10 tapers from the forwardmost points of the first and second side edges 14, 15 through the nose section 16 to the leading driving edge 11. The underneath surface of the ground anchor 10 is provided by the arcuate surface 13, the concave surfaces 17 and 18 and the rib 19.

The underneath surface acts to enable the ground anchor 10 to be driven into the ground and then pivoted to a "load locked" condition, as will be described later.

In Figure 2 it can be seen that in side elevation the ground anchor 10 is generally triangular in shape, whilst in Figures 5, 6, 7 and 8 it can be seen that in a transverse cross section through the part of the anchor providing the arouate lower surface 13, the anchor 10 is bell shaped. The anchor 10 has generally concave side surfaces 20 and 21 which extend from the side edges 14 and 15 of the anchor upwardly to upper edges 23, 24 which define the borders between the side surfaces 20 and 21 and an upper surface 25, seen most clearly in Figure 4. The upper surface 25 extends from the forward driving edge 11 to the rearward pivot edge 12, as can be seen in Figures 2 and 4. The width of the upper surface 25 narrows rearwardly from the leading edge 11 to a central waisted portion and then increases rearwardly from the central waisted portion to where the upper surface 25 meets the rear pivot edge 12. Thus the upper surface 25 has three sections, a nose portion 25a, a central waisted portion 25b and a rearward portion 25c.

The side surfaces 20, 21 and the upper surface 25 together provide a load reacting surface for the anchor, which supports an overburden when the ground anohor is "load locked" in position at a desired depth in the ground.

The ground anchor 10 is provided with an anchor eye 26 which extends between and opens on to the ground anchor side surfaces 20 and 21. It can be seen clearly in Figures 7 and 8 that the anchor eye is provided by a bore 29 which extends across the anchor 10. The anchor eye 26 provides a means for the attachment of a strap, as will be described later.

Figures 3, 4, 5, 7 and 8 show how a slot is provided in the anchor which opens onto the upper surface 25. The slot has two parts. The slot has a slot mouth 30 and a slot throat 31. The slot mouth 30 presents a generally rectangular opening in the nose portion 25a of the upper surface 25. The slot throat 31 extends from the slot mouth 30 rearwardly, extending from the nose portion 25a of the upper surface 25 through the central narrow waisted portion 25b to open rearwardly in the rearward portion 25c of the upper surface 25. The slot throat 31 also presents a rectangular opening in the upper surface 25, but the rectangular opening of the throat 31 is narrower in width than the opening presented by the slot mouth 30.

As illustrated by the dotted lines in Figure 4 and as seen in the cross-section of Figure 8, the slot throat 31 has a portion 31a forward of the anchor eye 26 which has a width corresponding to the width of mouth 30 and a rearward portion 31b of a narrower width which corresponds with the width of the opening of slot 31 in the upper surface 25. The throat 31 is aligned with and connects to the bore 29 forming the anchor eye 26. The slot mouth 30 and forward portion 31a of throat 31 allow the introduction of one end of a strap (described later) to the anchor eye 26, with the forward portion 3la of throat 31 allowing the guiding of the strap end to the anchor eye 26 and with the rearward portion 31b of the throat 31 allowing pivoting of the inserted strap once located in the anchor eye 26, but preventing rearward translational movement of the strap end beyond the anchor eye 26.

As is illustrated in Figures 3 and 7, the ground anchor 10 has a socket provided by a closed bore 33 provided which extends forwardly from a bore mouth 34 provided in the rear portion 25c of upper surface 25, the closed bore extending from the bore mouth 34 forwardly to a planar front abutment surface 35, shown in Figure 3. The bore 33 is circular in cross-section as can be seen in Figures 7, 8 and 9.

The ground anchor is preferably injection moulded in plastic, e.g. nylon. All of the above described features of the ground anchor 10 are preferably formed as integral parts of a single moulded component.

Figure 9 shows a strap for attachment in use with the ground anchor of Figures 1 to 8. The strap is preferably injection moulded in a plastic material, for instance nylon; with all the features of the strap 40 described below formed as integral parts of a single mcuided component. The strap 40 has a pivot end part 41, which is shown in detail in Figures 16 to 19. The strap 40 has a lead end part 42, which is shown in detail in Figures 12 to 14. Between the lead end -10 -part 42 and the pivot end part 41 there extends a ratohet section 43, which is shown in detail in Figure 15.

The pivot end part 41 of the strap 40 is a part whioh is secured to the ground anchor such as described in Figures 1 to 8. The pivot end part 41 of the strap 40 has a shaft 44 formed of two haif-shafts 44a and 44b, which extend perpendicularly out from a supporting arm 45. The arm 45 has two flat side surfaces 46 and 47 which are parallel to each other and which each extend perpendicularly to the plane of the upper surface 49 of a plate section 50 which partly overlaps with the supporting arm 45. This can be seen in clearer detail in Figures 16 and 17. In Figure 16 it can be seen that each of the half-shafts 44a and 44b has a circular cross-section. The supporting arm 45 when viewed in cross-section as seen in figure 16 can be seen to have a flat upper surface 50 and a parallel flat lower surface 51. At the end of the supporting arm 45 where the shaft 44 is located, the arm 45 has a curved surface 52, which has a portion which matches the radius of curvature of the shaft 44. This is important so that the strap 40 can rotate in journals provided by the anchor eye 26.

The supporting arm 45 also has tapering rear surfaces 53 and 54, where the arm 45 tapers from a maximum thickness h1 to the thickness h2 of the side walls 55 and 56 of the ratchet section 43 of the strap 40. This can be seen in Figure 16.

In Figure 17 it can be seen that the width w of the suppcrting arm 45 is much less than the width w2 cf the ratchet section 43 of the strap 40. There is a need to avoid a weak point in the strap which could cause the strap to -11 -fail and the reiative heights h-and h2 and widths w-and w2 of the supporting arm 45 and the ratchet section 43 of the strap 40 are chosen with this in mind, together with the provision of an overlapping seotion 57 (see Figure 16) where the plate section 59 and the supporting arm 45 extend co- termincusly -The ratchet section 43 of the strap 40 has a saw tooth ratchet form integrally formed therein as can be seen in Figure 15. The ratchet secticn 43 has two side walls 55 and 56 which extend parallel with each other, spaced apart with the ratchet section extending between them. The maximum height of the teeth of the ratchet is h3, which is less than the height h4 of each of the walls 55 and 56. :is

The lead end part 42 of the strap 40 is illustrated in detail in Figures 12 to 14. This comprises a key shaped aperture 60 through the strap 40 located between a pair of side walls 61 and 62 contigucus with respective side walls 55 and 56, but of a height h.. greater than the height h4.

The side walls 61, 62 each have a ramped section, e.g. 63, which steadily increases in height from the point at which the walls 61 and 62 meet the walls 55,56 to the maximum height of the walls 61 and 62, the walls 61 and 62 having a straight section of maximum height. This is most clearly seen in Figure 12. The key shaped aperture 60 has a section of greatest width 60 nearest the ratchet section 43, and then a tapering section 16b, which narrows to a slot section 60c.

The purpose of the key shaped aperture 60 is to allow two straps 40 to be interengaged end to end. The shaft 44 of a -12 -first strap can be inserted through the widest section OOa of the aperture 60 in a second strap and then siid towards the end of the lead end part 42 of the second strap, with the relevant supporting arm 45 of the first strap sliding through the tapering section 6Db of the aperture in the second strap to locate in the slot 60c. As long as the connected straps remain in tension, they are securely connected to each other, with the shaft 44 of the first strap engaging a surface surrounding the slot 6Cc of the second strap. There can be seen in Figure 31 a schematic image of two straps 40 connected end to end and such connected straps are shown in use in Figure 32, as will be described later.

Figures 20 to 26 show the cap 70 used by the invention. The cap 70 is shown in an underneath view in Figure 20 and it can be seen that the cap is circular when viewed in plan and on its underneath surface has supporting ribs 71, 72, 73, 74 which extend across the diameter of the cap 70, as well as an annular rib 75 which extends around the periphery of the cap 70 and an annular rib 76 of lesser diameter than the exterior peripheral annular rib 75. The ribs together provide strength to the cap. The ribs extend out of a top plate 77 which provides a planar top surface 78.

A U-shaped slot is provided extending through the cap 70, the U-shaped slot extending from an opening in the planar upper surface 78 down through a central hub portion 80 provided for the cap 70, the ribs 71, 72, 73 and 74 extending from the hub 80.

-13 -As best seen in Figure 24, a resilient arm 81 is provided to form part of the U-shaped slot 79. The arm 81 is formed integrally with the boss 80, with the arm 81 extending from a lowermost point 82 where it meets the boss 80 in a oantilever fashion upwardly towards the upper surfaoe 78 of the oap 70. The arm has a front faoe provided with a ratohet seotion 83 whioh has a saw tooth ratohet form as shown in Figure 26. The wall 84 faoing the front face 83 of the resilient arm 81 is smooth, but tapers from a midpoint 85 both upwardly and downwardly, so that the midpoint 85 provides the narrowest spacing between the wall 84 and the faoing ratohet 83.

The U-shaped slot 79 matches the U-shaped cross-section of the lead end part and the ratchet section 43 of the strap 40. Such a U-shaped cross-section can be seen for instance in Figure 14. The lead end part 42 of the strap 40 will be inserted through the aperture defined by the U-shaped slot 79 in the lower surface of the boss 80 and then will be slid through the slot 79 and pulled upwardly to extend above the planar surface 78. The ratchet face 83 of resilient arm 81 will engage the ratchet section of the strap 40 so that the strap 40 can be inserted in only one direction and cannot be pulled out of the cap in the opposite direction. This will be described later with reference to Figures 30 and 32.

The method of use of the apparatus described previously will now be described with reference to Figures 27 to 32.

Initially a strap 40 is secured to a ground anchor 10, as illustrated in Figure 27. This is done by inserting the shaft 44 into the slot mouth 30 (see Figure 4) and then -14 -sliding the shaft 44 away from the leading forward driving edge 11, with the supporting arm 45 fitting into and sliding along the slot throat 31. The resilient plastic of the anchor 10 and the strap 40 allows a limited amount of deformation so that the shaft 44 can be compressed and the walls of the slot throat 31 can be compressed as the shaft 44 moves towards the anchor eye 26. When the shaft 44 aligns with the anchor eye 26, the shaft 44 extends into and becomes secured in and journalled by the anchor eye 26. The shaft 44 then allows the strap 40 to be rotated relative to anchor 10.

Figure 28 shows the start of the installation process for the ground anchor. In the Figure there can be seen a driving rod 90 which is used to drive into ground 91 a ground anchor 10. The driving rod 90 is cylindrical and has its lower most end inserted in the socket provided by the closed bore 33 (see Figure 3) of the anchor 10, with an end surface of the drive rod 19 abutting the abutment surface 35 at the end of the closed bore 33. The drive rod 90 will be subject to a percussive force, applied e.g. by hammer used by an operative and the drive rod will be used to drive the ground anchor 10 to a desired depth below the surface of the ground 91.

In Figure 28 it will be seen that the anchor 10 is driven into the ground 91 with a strap 40 secured thereto. The anchor 10 drags the strap 40 down into the ground 91 as it is driven into the ground.

Once the anchor 10 has been driven to a desired depth in the ground 91 then the drive rod 90 is removed from the closed -15 -bore 33 and the drive rod 90 is withdrawn from the ground entirely. Then a tension force is applied to the strap 40 as indicated by the arrow 92 in Figure 29. This causes the anchor 10 to rotate in the direction of the arrow 93 of Figure 29, the anchor 10 rotating about the rearward pivot edge 12 of the anchor 10. The ground anchor 10 is rotated to a "load locked" position in which the upper surfaces 20, 21 and 25 of the ground anchor are exposed to the weight of the overburden of soil overlying the installed anchor 10.

In Figure 30 the anchor apparatus of the invention can be seen in use securing a ground sheet 94 on top of the ground 91. The ground sheet 94 could be of plastics material or could be coir matting or could be a tarpaulin used on a waste site. With the anchor 10 installed to a desired depth, the strap 40 is threaded through a suitable aperture in the ground sheet 94. Then a cap 70 is slid down over the lead end part 42 of the strap 40 until the cap 70 engages the top of the ground sheet 94. The ratchets provided on the strap 40 and in the cap 70 will engage with each other so that the cap 70 can be slid down into engagement with the top of the ground sheet, but then the cap 70 will resist any motion of the cap 70 upwardly along and relative to the strap 40 towards the lead end 42 of the strap 40. Subsequently, any loading on the ground sheet 94, e.g. wind loading, acting to lift the ground sheet 94 away from the underlying ground 91 will be resisted by the engagement of the cap 70, which is itself held in place by the tensile force applied by the strap 40, which is secured using the ground anchor 10. The arrangement will be able to resist 60/65kg of loading.

-16 -For some soil conditions, e.g. for marshy conditions, it may be desired to install the ground anchor 10 at a greater depth in order that there is a greater weight of overburden of soil acting on the anchor 10 to react to any loading on the anchor 10 acting to pull the anchor 10 out of the soil.

In Figure 31 (as previously described) two straps 40 are connected end to end. Then the connected straps are attached to a ground anchor 10, in the manner previously described and then the ground anchor 10 is driven into the soil 91 as shown in Figure 32 to a depth which is twice that of that shown in Figure 30. The ground sheet 94 is then secured in place by the cap 70 as described above.

Any number of straps 40 could be interengaged to allow the ground anchor 10 to be driven to a range of desired depths.

The use of ground anchor apparatus as described above is particularly beneficial where the soil Is of a granular material, because existing pegs are difficult to secure firmly in place in such soils. The ground anchor apparatus is ideal for securing in place landfill liners, since landfill itself provides a poor medium for securing of pegs.

Instead of using the cap 70 as illustrated above, the ground anchor 10 and strap 40 could be used with a plate like cap like that described above which is additionally provided with an eyelet to allow the attachment of e.g. a guy rope.

Indeed, instead of using a plate like cap as described above, a cap could be used which is formed as an eyelet In the case that it is to be used simply to secure guy ropes.

Furthermore, some ground sheets are mats which have ribs on the underside and a cap 70 could be used which would lie -17 -below the ground sheet, engaging the ribs on the underside of the ground sheet.

Preferably the anohor 10 the strap 40 and the cap 70 are all injection moulding plastic components, e.g. injeotion moulded in nylon. However, the cap could be made from a glass filled polyoarbonate for strength, if desired. Use of plastics provides for ease of manufacture, a lower price point and also good durability, so that the ground anchors could last for instance for 50 years even when exposed to brackish water, something which is difficult to aohieve with a metal anchor.

The ground anchor apparatus will be supplied as a kit of parts, comprising of separate elements of the ground anchor 10, the strap 40 (or a plurality of straps 40) and a cap 70, or an equivalent to cap 70. The kit could also comprise a hammer and a driving rod in order to drive the ground anchor into the ground and perhaps a knife or scissors to allow excess any strap length, protruding above the top surface of cap 70, to be removed once the ground sheet has been secured in place.

Claims

-18 -Claims 1. Ground anohor apparatus oomprising: a ground anchor; a driving rod locatable in a socket provided in the ground anchor; a strap securable at one end thereof to the ground anchor, the strap having a strap ratchet provided by a set of teeth; and a cap having a slot therethrough through which the strap can be inserted, the cap having a cap ratchet provided by at least one cap tooth,*wherein: the ground anchor can be driven to a desired depth in ground by application of force to the driving rod when located in the socket; the strap secured to the ground anchor can be dragged into the ground as the ground anchor is driven to the desired depth, with a second end of the strap left above ground level; and the second end of the strap can be inserted through the slot in the cap with the cap ratchet engaging the strap ratchet.
2. Ground anchor apparatus comprising: a ground anchor; a driving rod locatable in a socket provided in the ground anchor; a plurality of straps interengageable end to end, with a first strap seourable at one end thereof to the ground anchor and at least a second strap having a strap ratchet provided by a set of strap teeth; and -19 -a cap having a slot therethrough through which the second strap can be inserted, the cap having a cap ratchet provided by at least one cap tooth; wherein: the ground anchor can be driven to a desired depth in ground by applioation of a force to the driving rod when located in the socket; the strap secured to the ground anchor can be dragged into the ground as the ground anchor is driven to the desired depth, with a free end of the second strap left above ground level; and the free end of the seccnd strap can be inserted through the slot in the cap with the cap ratchet engaging the strap ratchet.
3. Ground anchor apparatus as claimed in claim 1 or claim 2 wherein the ground anchor is moulded as a plastic component.
4. Ground anchor apparatus as claimed in claim 3 wherein the strap is moulded as a moulded plastic component.
5. Ground anchor apparatus as claimed in any one of claims 1 to 4 wherein: the ground anchor is provided with an anchor eye extending widthwise across the anchor and with a slot having a slot mouth in an exterior surface of the ground anchor and slot throat extending lengthwise along the anchor between the slot mouth and the anchor eye; the strap or the first strap is provided at a pivot end thereof with a shaft prcvided on a supporting arm; wherein -20 -the shaft is insertable through the slot mouth and along the slot throat to be engaged and journailed in the anchor eye, with the shaft rotating in the anchor eye to allow rotation of the ground anchor relative to the strap secured thereto.
6. Ground anchor apparatus as claimed in claim 5 wherein: each strap is provided at a lead end thereof, opposite to the pivot end thereof, with a strap aperture through which a shaft of another strap can be inserted; and the strap aperture has a slot for receiving the supporting arm of the shaft; whereby: the shaft can be inserted through the strap aperture and the associated support arm then slid in the strap slot to a position in which the shaft engages a surface of the strap surrounding the strap slot.
7. A method of use of ground anchor apparatus comprising: securing a first end of a moulded plastic strap to a moulded plastic ground anchor; fixing a driving rod in a socket provided in the ground anchor and using the driving rod to drive the ground anchor to a desired depth in ground with the ground anchor dragging into the ground the strap secured thereto, while leaving a free end of the strap above ground level; removing the drive rod from the socket in the ground anchor and withdrawing the drive rod from the ground; pulling on the free end of the strap to rotate the ground anchor in the ground to an orientation in which -21 -load reacting surfaces of the ground anchor support an overburden; and inserting the free end of the strap through a siot in a cap with a set of strap teeth of a strap ratohet provided on the strap engaging at least one oap tooth of a cap ratchet, whereby the cap can be secured on the strap.
8. A method of use of ground anchor apparatus comprising; interengaging end to end a plurality of moulded plastic straps; securing a first end of a first strap of the interengaged plurality of straps to a ground anchor; fixing a driving rod in a socket provided in the ground anchor and using the driving rod to drive the ground anchor to a desired depth in ground, with the ground anchor dragging into the ground the interengaged straps secured thereto, whilst leaving a free end of a second strap above ground level; removing the drive rod from the socket in the ground anchor and withdrawing the drive rod from the ground; pulling on the free end of the second strap to rotate the ground anchor in the ground to an orientation in which load reacting surfaces of the ground anchor support an overburden; and inserting the free end of the second strap through a slot in a cap with a set of strap teeth of a strap ratchet provided on the strap engaging at least one cap tooth of a cap ratchet, whereby the cap can be located on the straps.-22 -
9. A method as claimed in claim 7 or claim 8 wherein the ground anohor apparatus is used to secure in place a sheet, with the free end of the/the second strap extending through an aperture in the sheet and the cap slid along the free end to engage a top surface of the sheet.

1O.Ground anchor apparatus substantially as hereinhefore described with reference to and as shown in the accompanying drawings.