When storing bulk products it is often desirable to contain the product within a predetermined area. Permanent structures can be built for this purpose, but often a temporary structure is preferred.

These temporary structures often take the form of a sectional freestanding wall. These are quick to assemble and can easily be built by a single individual with a forklift. Since the sections for the wall are freestanding, they may move if knocked or pushed. To avoid this, it is possible to fix the blocks to the ground. This is usually done by placing the blocks in the correct location on the ground and drilling holes in the concrete through holes in the base of the wall section. Anchor bolts are then passed through the holes in the base of the wall and into the holes in the ground to secure the base of the wall section to the ground. This ground fixing can be problematic, particularly if the holes in the base of the wall section are not easily accessible.

It is an object of the present invention to provide a more convenient freestanding wall, method of erecting a freestanding wall and method for securing a freestanding

wall to the ground.

According to the invention there is provided a reinforced concrete wall section for a freestanding wall having a base portion, a front portion and a rear portion, the front portion and rear portion extending from the base portion to form front and rear faces of the wall section, the front and rear faces of the wall section each having two edge portions, at least one of the front and rear faces having pre-formed holes in both the edge portions for receiving fixing means.

Also according to the invention, there is provided a method for creating a free standing wall from reinforced concrete wall sections having a base portion, a front portion and a rear portion, the front portion and rear portion extending from the base portion to form front and rear faces of the wall, the front and rear faces of the wall having two edge portions, at least one of the front and rear faces having pre-formed holes in both the edge portions, the method including the steps of: a) using a forklift to move a wall section into place, with the front and rear faces forming the front and back of the wall ; b) using the forklift to place a next wall section adjacent to the previous wall section such that the front faces are in substantially the same plane and the rear faces are in substantially in the same plane and there is

substantially no gap at the join between the wall sections; c) using the pre-formed holes in the neighbouring edge portions to receive fixing means to attach a securing member across the join between the adjacent wall sections; and d) repeating steps (b) and (c) until the wall is of the desired length.

It should be understood that all the wall sections could be positioned before they are secured together with the securing member, or the securing member could be fixed in place as each wall section is located to achieve a similar result. So it does not matter in which order steps (c) and (d) are performed. It should be noted that step (c) can also be performed in two stages, by fixing the securing member to one wall section before it is located, as will be described in more detail later.

By providing pre-formed holes in both the'edge portions of a face of the wall section, a securing member may be attached to neighbouring edge portions to secure the wall sections together.

Securing the wall sections together provides a much stronger wall. The wall sections are no longer free to move individually, but many sections must move together if one is pushed or knocked. To move many wall sections

together takes a much greater force than to simply move one section, so the wall is more resistant to deformation.

The pre-formed holes in the edge portions of the wall section are for receiving fixing means. The fixing means may take the form of a bolt, screw or similar threaded fixing device and if this is the case, the inner walls of the pre-formed hole may be threaded. The fixing means could be a concrete anchor bolt or chemical resin and in this case the inner walls of the hole may be rough to increase friction. The fixing means may have a bayonet fitting similar to some light bulbs and in this case the hole would be adapted to accept and hold such a fitting securely. For convenience, the invention will be described hereafter with reference to a preferred embodiment using bolts and boltholes, but it will be understood that the invention is not limited to this embodiment.

Preferably the pre-cast boltholes are permanently linked to the reinforcing structure within the concrete. This means that when the securing member is secured to adjacent wall sections with bolts, the reinforcing structure within the wall sections is effectively tied together to form a stronger structure than would have been formed with the bolt holes attached to the concrete alone.

In a preferred embodiment, the securing member is a strap with holes corresponding to the pre-cast boltholes of the edge portions. A strap has the advantage that that it will effectively seal part of the gap between the two wall

sections. This means that if, for instance, a granular bulk solid is being stored behind the wall, there is less chance of bulk solid leaking through the gap. The strap is preferably made from metal, as this would provide a strong, durable securing member.

It should be understood that the securing member may comprise a number of members that link corresponding holes in the edge portions of the wall sections.

Preferably when the first portion of the securing member is attached with bolts to an edge portion of a face of a wall section, the second portion of the securing member extends from the wall section substantially parallel to the plane of the face to which it is attached. This has the advantage that when wall sections are placed next to each other the securing member will be in substantially the correct orientation to be secured to the adjacent wall section.

Recesses may be provided for the strap in the edge portions of the wall section such that, when attached, the strap does not protrude substantially from the face of the wall section. If the strap does not protrude from the faces of the wall sections, the wall presents a smoother surface and it is therefore easier to use mechanical means to pick up and transport the bulk solid from near the wall. If there are protrusions from the surface of the wall, these could be knocked by the mechanical means, possibly damaging the wall, or mechanical means.

Preferably at least one of the front and rear portions is inclined such that the distance between the front and rear faces decreases with distance away from the base portion.

This results in a wall section with a triangular outer cross section. Since the centre of gravity is near to the ground, the wall section will resist tipping over. This profile will also result in less concrete being required than for a rectangular block with a base portion of similar dimensions. To reduce the weight and cost still further, the wall section may have a hollow, preferably a substantially triangular hollow, between the front and rear portions such that the wall has a cross section similar in shape to a capital letter"A". This provides a convenient lifting point for forklift trucks. The operator can simply slide the tines of the forklift into the hollow and lift the wall section without the need for lifting straps or chains. It should be understood that there are many shapes of hollow that will perform this function, but a triangular shape is preferred.

Preferably the edge portion of both the front and rear faces of the wall section have boltholes therein. This means that the wall can have securing members over the gaps on both the front and rear surfaces of the wall. To be deformed by a force, the gaps between the wall sections on one side of the wall must increase in size. If the securing member is preventing this change the wall is more difficult to deform. Securing members on both sides of the wall mean that the wall can resist forces from either side

more effectively.

The base portion may include holes through which fixings may be passed to attach the wall section to the ground.

This allows each wall section to be secured to the ground and hence provide a more permanent fixed wall structure.

The holes in the base portion may allow bolts to be passed through to attach the wall section to a base member with corresponding bolt holes to increase the overall height of the wall section. This provides a quick and reliable method for adjusting the height of the wall section. This means that the industry standard heights of 2.4 m, 3.0 m and 3.6 m can be achieved with one master wall section and different base units. This greatly reduces the cost for moulds, as different main wall section moulds are not needed, and the moulds for the base units are smaller and cheaper.

Preferably, the base units can be secured together in the same way as the wall sections, by using bolts and securing members. Preferably, for a wall to be constructed including base units to increase the height, the securing member is elongate and extends beyond the base portion of the wall section so it may be attached to the base unit.

This means that the securing member is securing four blocks together.

Preferably securing straps are attached to edge portions at one end only of the wall sections prior to locating the

wall sections; the method may then include the steps of: 1) ensuring that the forklift picks up the wall sections from the end of the wall section not including the securing strap ; and 2) when the forklift is positioning. the next wall section, using the securing strap as a guide to correctly position the wall section as the wall section is lowered into place.

Since the securing straps are attached prior to assembly, and they can be used as a guide, the time required to correctly locate the strap on the wall section is greatly reduced. This means that a secured wall can be erected quickly and simply.

Although the wall may be simply placed on a surface and linked together, for additional strength the wall sections may be secured to the surface. It should be noted that the wall sections need not be linked together to be secured to the surface, although in a preferred embodiment the wall sections are secured to each other and to the surface.

Accordingly the invention also provides a system for erecting a concrete wall on a surface comprising a wall section and a ground fixing for securing to the surface, the wall section having a base portion, a front portion and a rear portion, the front portion and rear portion extending from the base portion to form front and rear

faces of the wall section, the base portion including at least one fixing hole therethrough and a recessed portion in the bottom surface thereof, the recessed portion allowing the wall section to be located over the ground fixing such that at least part of the ground fixing is within the recess when the base portion is located on the surface, and the at least one fixing hole enables a fixing member to secure the wall section to the ground fixing.

Also according to the invention there is provided a method for securing a freestanding wall section to a surface, the wall section including a base portion, a front portion and a rear portion, the front portion and rear portion extending from the base portion to form front and rear faces of the wall section, the base portion including at least one fixing hole therethrough and a recessed portion, the method including the steps of: a) attaching a ground fixing to the surface in the desired location of the wall section; b) inserting a fixing member through the fixing hole and securing the fixing member in place; c) locating the wall section in the desired location such that at least part of the ground fixing is within the recessed portion of the base portion ; and d) engaging the fixing member with the ground fixing.

By enabling the units to be secured to ground fixing already fixed to the ground the time during which a forklift is required is reduced greatly as the wall sections can be secured quickly to the existing ground fixing. Fixing the wall to the ground also increases the strength of the resulting wall.

If the wall has a cross section similar to a capital letter"A"it becomes difficult to drill into the ground through the base portion due to space restrictions. This means that a traditional ground fixing is not feasible. By fixing a ground fixing to the ground before the wall section is put in place this problem is alleviated and the blocks can be located and secured much more quickly.

The ground fixing could be a single unit for each wall section, or could be an elongate structure to which many wall sections could be secured. The term"fixing member" is used herein to include any means which may pass through fixing holes in the base portion and engage with the ground fixing to secure the wall section to the ground fixing, for example a bolt, clip, hook or rod driven into the ground fixing. For simplicity, the fixing member shall be referred to hereinafter as a"fixing bolt"according to a preferred embodiment.

Preferably, the fixing bolt for securing the wall section to the ground fixing comprises an elongate body for passing through the fixing hole in the base portion, an engaging portion for engaging with the ground fixing and

means for the securing the fixing bolt to the base portion. Preferably the engaging portion of the fixing bolt comprises a portion extending substantially perpendicular to the elongate body to engage with the ground fixing. This enables a simple attachment to the ground fixing including a rail member involving dropping the engaging means past the rail with the extending portions substantially parallel to the rail member. Once the engaging portion is below the level of the rail member, the fixing means is rotated by about 90° and lifted so that the engaging portion engages with the rail member.

Preferably the ground fixing includes at least one rail member. This rail member may extend the length of the wall or be in sections beneath the wall. The use of a rail member provides a greater tolerance for errors in the location of wall section along the rail member.

The rail member may be supported above, and secured to, the surface by supporting members. This enables the above securing operation to be achieved much more easily as the engaging portion can easily be located below the rail member without the need for the rail member to be specially adapted.

Preferably at least one supporting member is located within and extends across substantially the entire width of the hollow beneath the wall section. This helps prevent the wall section from moving sideways.

Preferably the ground fixing comprises at least one rail member raised above the surface by supporting members, the fixing means including a fixing means comprising an elongate body and an engaging portion extending substantially perpendicular to the elongate body, step (4) of the method including the steps of; i) lowering the engaging portion of the fixing bolt to a level below that of the rail member; ii) rotating the elongate body of the fixing bolt such that the engaging portion is moved to a position below the rail means ; and iii) raising the engaging portion of the fixing means so that it engages with the rail system.

Although the invention has been described herein with reference to the storage of bulk solids, the invention is equally applicable to any situation where a freestanding wall is required.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows a wall section according to the invention ; Figure 2 shows a close up view of a bolthole and shows some of the reinforcing within the concrete wall section ; Figure 3 shows an exploded diagram of how two wall sections may be connected together using a securing strap ; Figure 4 shows a wall constructed according to the invention; Figure 5 shows a wall section with a base unit ; Figure 6 shows the inverted"V"shape of the securing straps when attached to one end of a wall section; Figure 7 shows a wall block secured to the ground using a ground fixing system ; Figure 8 shows the ground fixing system of Figure 7 in greater detail; and Figure 9 shows a clearer view of fixing bolt for the

ground fixing system of Figure 8.

Figure 1 shows a wall section 1 having a substantially rectangular base portion 2, a front portion 4 and a rear portion 6. The front portion 4 and rear portion 6 both rise at an angle from opposing edges 10,12 of the base portion 2 and meet at an apex 8 above, and midway between the edges 10,12 of the base portion 2. The front portion 4 and rear portion 6 each has a respective face 14,16.

Between the front portion 4 and the rear portion 6 there is a triangular hollow 18 passing through the wall section 1 such that the cross section of the wall section is similar in shape to a capital letter"A".

The faces 14,16 have recessed edge portions 20 at opposing sides 22,24 of the wall section 1. The recessed edge portions 20 include pre-cast boltholes 26. The boltholes 26 are distributed along the length of the edge portions 20. It should be understood that the edge portions 20 do not need to be recessed for the invention to be worked.

Figure 2 shows a close up view of one of the boltholes 26 from Figure 1. For the purposes of illustration, the concrete in this figure has been removed and only the outlines of the wall section 1 remain. In this figure a reinforcing steel grid 30 can be seen. The grid 30 is cast within the wall section 1 to provide added strength. The pre-cast bolthole comprises a metal tube 32 with an inner face 36 and an outer face 38. A thread pattern 34 is formed on the inner face 36 so a bolt (not shown) may be

introduced and secured within the tube 32.

The reinforcing grid 30 is securely attached to the outer surface 36 of the tube 32 at two points 40,42 such that the tube 32 may not move without moving the grid 30. Once the grid 30 is cast within the concrete of the wall section 1, the tube 32 is securely held in place.

In Figure 3 two wall sections are shown. The features labelled in Figure 1 are given similar reference numerals, but the numerals of the first block will be incremented by 100 and the numerals of the second block will be incremented by 200.

Figure 3 shows two wall sections 101,201 being moved (arrow 50) together such that edges 124 and 222 are in close proximity. An elongate rectangular securing strap 52 with holes 54 corresponding to the pre-cast bolt holes 126, 226 in the neighbouring edge portions 120,220 may be attached (arrow 53) with bolts (not shown) to the edge portions 120,220 of the wall sections 101,201.

The securing strap 52 can be attached with bolts (not shown) to both edge portions 120,220 at the same time once the wall sections 101,201 are together. Alternatively the securing strap 52 can be attached to an edge portion of the wall section to be put in place second so the strap does not obstruct location of the wall sections. Once the second wall section is in place, the securing strap can be secured to the first wall section.

Figure 4 shows a wall 60 having a front face 62 and a rear face 64 constructed from wall sections 1 as shown in Figure 1 and connected together as shown in Figure 3.

The drawing shows six wall sections 1 connected together by ten securing straps 52, five on each face 62,64 of the wall. The securing straps are attached to the wall sections with bolts 68. It can be seen that the securing straps 52 cover joins 66 where the wall sections have been brought together. This means that it is less likely that a bulk solid contained behind such a wall 60 could leak through. The securing straps could entirely cover the join 66 between the two wall sections.

The method for constructing such a wall is simple and a wall can be constructed quickly by one person with a forklift truck (not shown).

For this example, the wall sections 1 already have securing straps 52 attached to the edge portions 20 of one side.

The forklift picks up a first wall section 1 by inserting the tines of the forklift into the hollow 18 through the wall section 1. It should be noted that the forklift should lift the wall section 1 from the side that does not have securing straps 52 attached. The wall section is transported to an end of the wall and orientated such that the side with the securing straps is at the far end of the

wall 60.

The forklift then picks up a next wall section 1 in the same way. This wall section is transported to the previously located section and is butted up against it. As the next wall section is lowered, the gradually tapering nature (best shown in Figure 6) of the extending portion of the securing strap can be used as a guide to aid the correct location of the next wall section.

This process is continued until the wall 60 has reached the desired length. At this point bolts 68 are inserted through the holes 45 in the securing straps 52 and into the pre-cast bolt holes 36 to attach the securing straps 52 to the wall sections 1.

Figure 5 shows a wall section 1, a base unit 72 and an elongate securing strap 84. The wall section is as in Figure 1, but includes holes 70 through the base portion 2 to allow bolts to pass through and secure the wall section 1 to the base unit 72.

The base unit 72 has pre-cast bolt holes 74 in a top surface 76 corresponding to the holes 70 in the base portion 2 of the wall section 1. The top surface 76 of the base unit 72 is arranged to allow the base portion 2 of the wall section to fit onto the base unit 72.

The base unit has front and rear faces 78,80 which include recessed edge portions 82 to match the edge portions 20 of

the wall section 1. The edge portions 82 of the base unit include pre-cast boltholes as shown in Figure 2.

The elongate securing strap 84 has holes corresponding to the pre-cast bolt holes in both the edge portions 20 of the wall section 1 and the edge portions 82 of the base unit.

When the wall section 1 and base unit 72 have been bolted together, a wall can be constructed in the same fashion as in Figure 3.

In Figure 6 a wall section 1 is shown with securing straps 52 attached to the edge portions 20 of one side 22. It can be seen that the each securing strap 52 has a first portion 90 attached to an edge portion 20 and a second portion 92 which extends from the wall section 1. The second portions 92 of the securing straps form an inverted "V"shape narrowing from the base portion 2 towards the apex 8.

When the wall section 1 is butted up against an already positioned wall section and lowered, the second portions 92 of the securing straps 52 slide over the edge portions of the other wall section. The inverted"V"shape guides the wall section 1 into the correct alignment as it is lowered.

Figure 7 shows a freestanding wall section 1, secured to the ground by a ground fixing 102. In this drawing, the

detail of the edge portions of the wall section is not shown. The wall section 1 includes a recessed portion 104 in the base portion 2 such that at least part of the ground fixing 102 may be located within the recessed portion 104 when the wall section 1 is located over the ground fixing 102.

The ground fixing 102 includes two rail members 106,108 that pass beneath the wall section 1 and run substantially parallel to the front and rear faces 14,16 of the wall section 1.

Support members 110 support the rail members 106,108 above the ground. The support members 110 are secured to the ground by bolts 112 and are aligned substantially perpendicular to the rail members 106,108. The support members 110 comprise a ground engaging portion 114 through which the bolts 112 pass and an upstanding portion 116 through which the rail members 106,108 pass.

The upstanding portions 116 are shaped such that when a wall section 1 is located over a securing member 110, the upstanding portion 116 matches the shape of the recessed portion 104.

Two fixing bolts 120 pass through the base portion 2 of the wall section 1. These fixing bolts 120 engage with the rail members 106,108 to secure the wall section 1 to the ground fixing 102. The fixing bolts are shown in more detail in Figures 8 and 9.

Figure 8 shows the ground fixing of Figure 7 more clearly and includes an embodiment of a fixing bolt 120. In this drawing it can be seen that there are a number of supporting members 110 spaced along the length of the rail members 106,108.

From this drawing and Figure 9 it can be seen that the fixing bolt 120 has a capital"T"shape. The body 122 of the fixing bolt 120 fits through holes (not shown) in the base portion 2. One end of the body 122 is threaded 124 to accept a nut 126.

At the other end of the fixing bolt 120, there is an engaging portion 128 that extends on opposite sides of, and at substantially 90° to, the body 122 of the fixing bolt 120.

To fix a wall section 1 to ground fixing 102 as in Figure 7 two fixing bolts 120 are first passed through the base portion 2 such that the engaging portion 128 is located within the recess 104 and the threaded portion 124 is accessible.

Nuts 126 are then screwed onto the threaded portions to prevent the fixing bolts 120 falling from the base portion 2.

The wall section 1 is then lifted into position over the ground fixing 102 and the nuts 126 removed or loosened.

The fixing bolts 120 are then rotated until the engaging portions 128 pass between the rail members 106,108 and lie beneath them at substantially 90° to the rail members 106,108 (as shown in Figure 8). The nuts 126 are then replaced and/or tightened such that the engaging portions 128 of the fixing bolts 120 engage with the rail members 106,108 and secure the wall section 1 in place.