WO2013056306A1

WO2013056306A1 - Shoring box system and method

Info

Publication number: WO2013056306A1
Application number: PCT/AU2012/001263
Authority: WO
Inventors: Paul Breen
Original assignee: Quickway Constructions Pty Ltd
Priority date: 2011-10-19
Filing date: 2012-10-18
Publication date: 2013-04-25
Also published as: AU2012325674B2; DE112012004108T5; NZ721381A; GB2511229B; GB201408638D0; NZ625161A; GB2511229A; US20140248093A1; AU2012325674A1

Abstract

A shoring box system (10) for use in a ground trench (60) includes a pair of shoring panels (12) and a number of elongate props (22). The props are attached to the two shoring panels to maintain the panels in an erected position in which they are spaced apart, with an open zone (19) between the panels. The props can be detached from the shoring panels while the shoring panels are in the erected position. In an embodiment each panel is hollow and has a lower opening (36) with a closure flap (38) for closing the opening, to enable filling material in the hollow to pour from the panel as it is removed from the trench. Also in an embodiment, each shoring panel is tapered in a downward direction.

Description

SHORING BOX SYSTEM AND METHOD

FIELD OF THE INVENTION This invention relates to a shoring boxes. More specifically, the invention relates to a shoring box system and to a method of using a shoring box system.

BACKGROUND TO THE INVENTION

It is frequently necessary to dig trenches in the ground, for example when laying pipes, or during other construction activities. There is an inherent danger that the walls of a trench can crumble and cave in, and this can pose a significant danger to workers operating within the trench. Accordingly, it is known to use shoring box systems for shoring up the walls of such trenches.

A typical shoring box system includes shoring panels which are positioned immediately adjacent to the trench walls, to prevent the walls from crumbling. Such a typical shoring box system is conventionally assembled before being placed in a trench. Indeed, in a typical shoring box system, the shoring panels are provided with inwardly projecting spigots, and props or struts are engaged with the spigots, typically by locking pins which are passed through aligned holes in the props and spigots, to lock the components together. The props typically extend between two opposite shoring panels, and maintain the panels in a spaced-apart relationship. This essentially prevents the shoring panels from moving towards each other, and thus enables the panels to suitably shore up the walls of the trench. Such conventional shoring box systems are generally not designed in a manner which facilitates the pouring of concrete floors or walls in the trenches. Firstly, once the shoring box system has been inserted in the trench, it is not possible to remove the props without removing the entire assembly from the trench. This is due to the manner of connection between the props and shoring panels as described above. The presence of the props, particularly lower props, could hinder the pouring of concrete floors into such trenches. The props, both lower and upper props, would also act as an obstacle that may prevent or hinder the pouring of concrete walls. Accordingly, as it is not practicable to construct walls which might serve to reinforce the walls of the trench, this role must continue to be performed by the shoring box systems. Accordingly, such conventional shoring box systems are designed to be used for the full duration of operations occurring in the trench. This could give rise to undesirable cost, as multiple shoring box systems may be required, especially when extensive lengths of trenches are involved, and especially when the trenches are in use for extended periods of time.

One of the types of trench in which shoring box systems may be employed, is a so-called pulling pit. This is a pit or cavity created especially to provide access to cables that extend along underground cable conduits. Such access is required in order to pull the cables inside the conduits. The pulling is typically performed by cable-pulling apparatus. This often necessitates the construction of floors in such pits to support the apparatus. However, in the traditional shoring box systems, the props are essentially fixed in place and do not provide sufficient space for the apparatus. Accordingly, it is usually required to remove the shoring box systems and construct concrete walls to reinforce the pit, so that the props are no longer present to prevent accommodation of the apparatus. However, as the purpose of such pits is limited to pulling the cables, it is often considered that the need to build such walls gives rise to a waste of resources.

Even if concrete walls are poured into such trenches as a means of replacing the shoring box systems, this gives rise to additional difficulties. For example, if the concrete is poured so that it is in contact with the shoring panels, as the concrete sets, a bond will be established between the concrete wall and shoring panel. When it is time to remove the shoring panels, significant force may be required, firstly to break the bond between the panels and the concrete walls, and also because of continued frictional engagement between the concrete walls and panels as the panels are withdrawn.

In addition, once such panels are removed, voids will be left between the walls of the trench and the outer faces of the newly poured concrete walls. Such voids could increase the risk of the trench walls crumbling as portions of the wall fall into the voids, and could thus result in the surrounding ground surface becoming unstable.

It is an object of the invention to overcome or ameliorate disadvantages of the prior art, or at least provide a useful alternative thereto. SUMMARY OF THE INVENTION

According to a fist aspect of the invention there is provided a shoring box system including:

a pair of shoring panels; and

a plurality of elongate props, each adapted for releasable attachment to the two shoring panels by prop connectors, so as to maintain the shoring panels in an erected position in which the shoring panels are spaced apart from each other with an interior zone between the panels, wherein the prop connectors are adapted to enable the props, when connected to the shoring panels, to be detached from the shoring panels while the shoring panels are in said erected position.

In a preferred embodiment, the prop connectors are adapted to enable the props to be detached from the shoring panels by movement of each prop at least partially laterally with respect to the longitudinal direction in which the prop extends.

Preferably, each prop connector includes a first connector portion on a respective prop and a second connector portion on a shoring panel, the first and second connector portions being releasably attachable to each other by means of being superposed on each other and a locking element adapted for releasably interlocking the first and second connector portions. In a preferred embodiment, each shoring panel has an upright operational orientation and includes a plurality of reinforcement elements each substantially traversing the height of the panel.

Preferably each reinforcement element includes an I-beam.

In a preferred embodiment, each shoring panel includes shoring panel walls, the walls of each shoring panel at least partly defining an interior space of that shoring panel, wherein the reinforcement elements are disposed in the interior space.

In a preferred embodiment, each shoring panel includes shoring panel walls, and is configured such that, when the shoring panels are in said erected position, a wall of each shoring panel facing into said interior zone is non- vertical so that an upper end of the wall is disposed more inwardly relative to the interior zone than a lower end of the wall.

Preferably, each shoring panel tapers in a downward direction.

In a preferred embodiment, each shoring panel has an opening to said interior space at or adjacent to a bottom extremity of the shoring panel. The shoring panel preferably includes a closure component which is movable between a closed position in which it is attached to at least one shoring panel wall of the respective shoring panel and extends over, and thereby substantially closes, the opening to the interior space of that panel, and an open position in which the opening is substantially uncovered by the closure component.

Preferably, the closure component is rotatably attached to the at least one shoring panel wall so as to be movable between said closed and open positions by rotation relative to the at least one panel wall. Preferably, the closure component is adapted to fall from its closed position to its open position under the effect of gravity. In a preferred embodiment, each shoring panel includes a first panel wall, and a second panel wall spaced from, and opposed to, the first panel wall, one of the first and second panel walls having a lower edge which is lower than a lower edge of the other of the first and second panel walls such that the bottom of the panel is substantially wedge-shaped.

Preferably said other panel wall is on the same side of the panel as said interior zone.

In a preferred embodiment, the pair of shoring panels and the props attached thereto together constitute a shoring panel unit, the unit being adapted for releasable connection to an adjacent said unit.

Preferably, each unit is adapted for such releasable connection to two adjacent units, one on each of two opposite sides thereof, so that said units together constitute a series of units.

Preferably, the adjacent units are adapted for said releasable connection by means of a connection element which is slidably engageable with at least one of the adjacent units.

Preferably, said at least one of the adjacent units defines an upwardly extending slot, the connection element being slidably receivable in the slot.

Also preferably, each of said adjacent units defines an upwardly extending slot, the connection element being slidably receivable in the slots.

According to a second aspect of the invention there is provided a method of using a shoring box system according to the first aspect of the invention, to reinforce a ground cavity having opposing cavity walls, the method including: A.1 disposing, in the cavity, shoring panels of the shoring box system such that the shoring panels abut two respective said opposing cavity walls; and

A.2 attaching said props to the shoring panels to maintain the panels in said erected position.

Preferably, step A.2 includes attaching said props such that there is a lowermost level of props, and at least one level of props above the lowermost level, the method further including:

B.1 after the props are so attached, pouring a concrete floor in the cavity;

B.2 allowing the poured floor to set;

B.3 after the poured floor has set, detaching the props in said lowermost level from the shoring panels.

Preferably, the method includes, after step B.3, building at least one wall on the floor, the wall extending above the level at which the lowermost level of props were disposed prior to said detachment. Preferably, the method includes:

detaching, from the shoring panels, each prop that is attached to the shoring panels, such that the shoring panels are not connected to each other; and

then removing, from the ground cavity, each shoring panel.

According to a third aspect of the invention there is provided a method of using a shoring box system to reinforce a ground cavity having opposing cavity walls, the method including:

disposing, in the cavity, shoring panel units according to the first aspect if the invention such that the shoring panels of each unit abut two respective said opposing cavity walls, wherein each pair of adjacent panels of adjacent units are interconnected to each other by a said connection element. According to a fourth aspect of the invention there is provided a shoring box system including:

a pair of shoring panels each having shoring panel walls, the walls of each shoring panel defining at least part of an interior space of that shoring panel, each shoring panel having an opening to that interior space at or adjacent to a bottom extremity of the shoring panel, each shoring panel further including a closure component which is movable between a closed position in which it is attached to at least one shoring panel wall of the respective shoring panel, and extends over, and thereby substantially closes, the opening to the interior space of that panel, and an open position in which the opening is substantially uncovered by the closure component; and

a plurality of elongate props attached to the two shoring panels so as to maintain the shoring panels in an erected position in which the shoring panels are spaced apart from each other with an interior zone between the panels.

According to a fifth aspect of the invention there is provided a shoring box system including:

a pair of shoring panels each having a shoring panel wall; and a plurality of elongate props, each attached to the two shoring panels so as to maintain the shoring panels in an erected position in which the shoring panels are spaced apart from each other with an interior zone between the panels,

wherein each shoring panel is configured such that, when in the erected position, the wall of the panel faces into said interior zone and is non- vertical so that an upper end of the wall is disposed more inwardly relative to the interior zone than a lower end of the wall.

Any discussion of the prior art in this specification is not intended, and is not to be construed, as any statement, implication or admission that that prior art constitutes part of the common general knowledge in Australia or anywhere else. BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which :

Figure 1 is a schematic end of view of a shoring box system according to an embodiment of the invention;

Figure 2 is a front view of one of the shoring panels of the system of Figure 1 ;

Figure 3 is a plan view of the panel of Figure 2;

Figure 4 is a schematic view, similar to that of Figure 1 , but showing the shoring box system located in a trench;

Figures 5a and 5b are schematic cross-sections showing details of the bottom end of the left-hand shoring panel as shown in Figure 1 , with its closure flap in a closed position and open position, respectively; Figure 6 is a plan view of adjacent shoring panels of two shoring box systems similar to the one shown in Figure 1 , the systems being joined together;

Figures 7a and 7b are detailed views of the circled part of Figure 6, showing the joint between the adjacent panels of the shoring box systems, in the separated and joined conditions, respectively;

Figure 7c is a different embodiment of the features shown in Figures 7a and 7b;

Figure 7d is a different embodiment of the features shown in Figure 7c; and

Figure 8 is a schematic representation of two shoring box systems joined together. DETAILED DESCRIPTION

Referring to the drawings, there is showing a shoring box system 10. The system 10 includes two shoring panels 12. Each shoring panel 12 has an outer wall 14 defining an outer face of the panel, an inner wall 16 defining an inner face of the panel, and two edge walls 18. The shoring panels 12 are in a spaced-apart relationship as shown, defining a substantially open zone 19 between them. Each shoring panel 12 is shaped so that its outer wall 14 and inner wall 16 converge on one another in a downward direction, whereby the panel tapers from its upper extremity to its lower extremity. More specifically, the inner walls 16 of the two panels 12 are each angled to the vertical such that the inner walls of the two panels diverge from each other in a downward direction.

Indeed, according to one preferred embodiment, the thickness of the top of each panel 12 is around 180 mm, while the thickness of the bottom of the panel is around 155 mm. Each panel 12, on its inner wall 16, has a lower and an upper support structure 20. Each support structure 20 is in the form of a box-section (rectangular section) beam, extending along the length of the panel 12. Each lower support structure, referenced as 20.1 , is attached to the respective panel 12 by bolts or other removable fasteners (not shown) whereby those support structures are removable from the relevant panels.

Each upper support structure, referenced as 20.2, is attached to the respective panel 12 in a permanent fashion, for example by welding. The system 10 also includes upper and lower props 22. Each prop 22 includes an elongate strut 24 of substantially rectangular or square cross- sectional shape, and a pair of attachment plates 26, joined to the strut at each of the two opposite ends 28 of thereof, so as to protrude beyond those ends. The walls 14, 16, 18 of each shoring panel 12 define an interior space 30 of the panel (see Figures 5a and 5b).

It will be noted that the outer wall 14 of each panel 12 has a lowermost edge 32 which is lower than the corresponding lowermost edge 34 of the inner wall 16 of that panel. Accordingly, the lower end of each panel 12 is substantially wedge-shaped.

An opening 36 to the interior space 30 is defined by the outer walls 14, inner wall 16 and edge walls 18 of each panel 12 (see Figure 5b).

Also provided are closure components 38, each attached to a respective shoring panel 12. Each closure component 38 is effectively in the form of a flap which is rotatably joined to the shoring panel 12, and more specifically, to the inner wall 16 of the panel, by means of a hinge 40. Accordingly the closure components 38 are referred to below as flaps.

As shown in Figures 5a and 5b, each closure flap 38 is movable between a closed position in which it extends across, and substantially closes, the opening 36, and an open position in which it does not cover the opening.

When the closure flap 38 is in its closed position, it forms part of the lower wedge shape of the respective shoring panel 12. As described in more detail below, according to a preferred embodiment as shown in Figures 6, 7a and 7b, each shoring panel 12 is provided, at each of its opposite ends, with connection means to enable the interconnection between two adjacent shoring box systems 10 (that is, between the shoring panels 12 of the two adjacent shoring box systems 10). It will be appreciated that each such shoring box system 10 effectively constitutes a separate modular unit, and will be referred to as such below.

It will be noted, in both the embodiment shown in Figure 3 and the embodiment of Figure 6, that each shoring panel 12 is reinforced by I-beams 42 which extend vertically within the interior space 30, between the inner wall 16 and outer wall 14 of the shoring panel.

For ease of reference, in Figures 7a and 7b, the left hand shoring panel 12 as shown (i.e. the shoring panel 12 of the left hand shoring box unit 10) is referenced as 12.1 , while the right hand panel as shown (i.e. the shoring panel 12 of the right hand shoring box unit 10) is referenced as 12.2. The particular I-beam 42 in the panel 12.1 closest to the shown edge of that panel is referenced as 42.1 , while the corresponding I-beam of the other panel 12.2 is referenced as 42.2.

The left-hand panel 12.1 is provided with a flange 44, which extends inwardly from the outer wall 14, and an L-section member 46. The L-section member 46 includes two flanges 48 and 50. The flange 48 extends towards the flange 44, so that these two flanges define a gap 52 between them, and, together with the nearest I-beam 42.1 , define a space 54, which essentially constitutes a slot in the left-hand panel unit 12.1 . The other flange 50 of the L-section member 46 extends parallel to the outer and inner walls 14 and 16 of the shoring panels 12.1 and 12.2.

The adjacent, right hand panel 12.2 is provided with an engagement plate 56. The engagement plate 56 is connected to the I-beam 42.2 by means of a connector portion 58. The flange 44, L-section member 46 and engagement plate 56 all extend substantially the height of the respective shoring panels 12.1 , 12.2.

As shown in Figure 7b, the two adjacent panels 12.1 and 12.2 can be interlocked by sliding the panels vertically with respect to each other such that the engagement plate 56 is received in the space 54, with the connector portion 58 passing through the gap 52.

It will be understood that the flanges 44 and 48 hold the engagement plate 56 captive in the slotted space 54, thereby preventing the two panels 12.1 and 12.2 from being pulled apart from each other.

In Figure 7c, there is shown an embodiment which uses a somewhat different means of connection of the two adjacent shoring box units 10 to that shown in Figures 7a and 7b. In the embodiment of Figure 7c, parts corresponding to parts in Figures 7a and 7b are indicated with similar reference numbers.

In this embodiment, instead of the connector portion 58 connecting an engagement plate 56 to the I-beam 42.2, it interconnects two similar engagement plates 56, with neither engagement plate, nor the connector portion, being attached to either of the shoring panels 12.1 , 12.2 of the two adjacent shoring box units 10. Indeed, the connector portion 58 and two engagement plates 56 form an independent connector element, generally referenced as 57, which has an l-shaped cross section along its length.

In addition, instead of the left hand shoring panel 12.1 having the flange 44 and the L-section member 46, it is provided with two-differently orientated L- section members 59, and these together define the gap 52. The other, right hand shoring panel 12.2 is essentially a mirror image of the left hand shoring panel 12.1 .

The connector element 57 formed by the connector portion 58 and two engagement plates 56 interconnects the two shoring panels 12.1 and 12.2 to each other by being slid into the slots constituted by the spaces 54 in the two panels. This can be achieved by placing the two panels 12.1 and 12.2 adjacent to each other, and then sliding the connector element downwards into these two slots, with the connector portion 58 extending through the gaps 52 and each engagement plate being accommodated in the slotted space 54 of a respective panel.

In Figure 7d there is shown an alternative embodiment to that shown in Figure 7c. In the embodiment of Figure 7d, the two adjacent shoring panel units 10 are at an angle to each other. This configuration may be used, for example, where the trench in which the shoring panel units 10 are placed is not straight, but curves. The shoring panel units 10 are placed at an angle to each other to follow the curved shape of the trench. In this case, the connector portion 58 of the connector element 57 is bent (or may be curved), to accommodate the different angles of the shoring panel units 10.

It will be understood that the configuration shown in Figure 7d relates to the joint between the two adjacent panels 12.1 and 12.2 on the inner side of the bend or curve in the trench. Because of the angle between the two shoring panel units 10, there will be a space between the two adjacent panels of the adjacent panel units on the outer side of the bend or curve (that outer side not being shown), and those two outer adjacent panels will therefore not be connected to each other by a connector element 57.

The shoring box system 10 can be used to shore up a trench 60 which has been dug in the surface of the ground 62, as shown in Figure 4.

Unlike conventional shoring box systems, the shoring box system 10 of the present invention need not be pre-assembled before being installed in the trench 60. Rather, each of the shoring panels can 12 be individually placed in the trench 60 such that the two panels are disposed opposite each other, with their outer walls 14 abutting the walls of the trench 60.

The props 22 can then be engaged with the shoring panels 12 to brace the panels in a spaced-apart relationship as shown in Figure 4. The props 22 can be secured to the shoring panels 12 by placing the attachment plates 26 of each prop in an overlapping relationship with the support structures of 20 of the two shoring panels, and then passing locking elements in the form of pins 64 through aligned holes (not shown) in the attachment plates and support structures. Thus, the attachment plates 26 and support structures of 20 may together be regarded as prop connectors for connecting the props.

Once the shoring panels 12 and props 22 have been assembled in this manner, concrete can be poured into the trench 60 to form a floor 68 of the trench. According to a preferred embodiment, concrete blinding 70 is first placed in the trench 60, and the concrete floor 68 then poured on the blinding.

In addition, starter bars 72 can be installed in the concrete floor 68 in the conventional manner, to provide reinforcement for walls that are to be constructed.

The lowermost props 22, when secured to the shoring panels 12, can hinder or prevent the building of concrete walls in the trench 60. However, given the nature of attachment between the props 22 and shoring panels 12, the lower props 22 can be easily removed, by removing the locking pins 64, and simply lifting the props away from the lower support structures 20.1 of the shoring panels. This method of removal essentially involves moving the props 22 laterally with respect to the direction in which they extend, and can therefore be achieved without the need to move the shoring panels 12.

The lower support structures 20.1 are then detached from the panels 20 by removing the fasteners (not shown) securing those structures to the panels. This essentially leaves each panel 12 with a substantially smooth face at the location where the lower support structure 20.1 was positioned prior to being removed.

It will be appreciated that, once the lower props 22 are removed, they no longer provide reinforcement to the shoring panels 12. On the other hand, the floor 68, once set, can serve to support the shoring panels 12. However, the distance between the upper props 22 and floor 68, is greater than the distance that existed between the upper props and lowermost props before the latter were removed. Accordingly, it is important that the shoring panels 12 be sufficiently strong to resist forces from the walls of the trench 60 which might cause the panels to deflect or collapse. According to one embodiment, the extent of such forces for which the shoring box system 10 may be designed is around 20 kilopascal (kPa). The I-beams 42 are orientated substantially vertically in the shoring panels 12 and assist in providing such strength to the panels (i.e. to brace the panels against deflection in a vertical plane). Thereafter, with the use of suitable form-work (not shown), concrete for forming side walls 74, indicated in phantom lines in Figure 4, can be poured in the trench 60. It can be seen that these walls 74 are formed such that the previously exposed parts of the starter bars 72 are embedded in the walls. As the lower support structures 20.1 were removed from the panels 12 as described above, they are not in the way of the walls 74.

However, the tops of the walls 74 are lower than the upper support structures 20.2, and those structures need not be removed in order to make room for the walls. Indeed, as mentioned above, those upper support structures 20.2 are attached to the panels 12 in a permanent fashion, and they serve to brace the panels against deflection in the horizontal plane, while the I-beams 42, as mentioned above, brace the panels against deflection in the vertical plane. The shoring panels 12 constitute the outer form-work for forming the concrete walls 74.

Once the walls 74 have set, the upper props 22 can be removed, in a similar manner to that in which the lower props were removed. The shoring panels 12 can also be removed.

While the embodiment described above has a lowermost level of props 22 and one level of props above that, in other embodiments, there may be one or more additional level of props above the lowermost level. In such embodiments, the walls 74 can be constructed in sequential stages. The first stage will be after the lowermost props 22 have been removed to accommodate that first stage of the wall. The next stage of the wall 74 will be built on top of the first stage after the next level of props 22 has been removed to accommodate that next stage of the wall.

In such embodiments, as the shoring panels 12 are likely to have greater heights than the types described with reference to the drawings, they will have to be designed to have sufficient strength to withstand potentially greater deflection forces. In particular, such design may take into account the potentially greater distance between the higher props 22 and the floor than between those props and lower props that have been removed.

It will be appreciated that, on removal of the shoring panels 12, the space vacated by the panels would constitute a gap between the walls of the trench 60 and the outer faces of the newly formed concrete walls 74. The presence of such gaps could be disadvantageous as it could allow material from the walls of the trench 60 to fall into the vacated space, and indeed could allow crumbling or collapse of the trench's walls.

According to an embodiment of the invention, filling material, such as suitable stable sand, can be placed in the interior space 30 of each shoring panel 12. This can be achieved either before the panels 12 are initially installed in the trench 60, or subsequent to installation of the panels in the trench. According to the preferred embodiment, the tops of the panels 12 are open and the filling material can be inserted via the open tops into the panels.

When it is desired to remove the shoring panels 12 from the trench 60, they can be lifted from the trench by suitable lifting means, such as winch or hoist, which can be connected to the panels at designated lifting points or eyes (not shown).

As the concrete walls 74 set, there is likely to be some adhesion between the outer faces of the concrete walls and the outer surfaces of the inner walls 16 of the shoring panels 12. As the shoring panels 12 are lifted, this will result in the adhesion between the shoring panels and concrete walls 74 being broken. However, in light of the tapering (wedge) shape of the shoring panels 12 as described above, and more specifically the angles of the inner walls 16, once the seal between each shoring panel and the relevant concrete wall 74 is broken, and after the panel has begun to be lifted, a space will be created between the shoring panel and the concrete wall. As a result, as the shoring panel 12 is lifted, there will be no engagement with, and hence no fictional resistance from, the concrete wall 74. In addition, as each shoring panel 12 has begun to be lifted, a space will be formed below the panel. Consequently, there will be nothing holding the closure flap 38 in its closed position, and it will thus be allowed to rotate, under the effect of gravity, to its open position as shown in Figure 5b. Once this occurs, the filling matter that had been placed inside the interior space 30 of the shoring panel 12 will be allowed to pour out via the opening 36 into the space below the panel 12. Thus, as the shoring panel 12 is removed in its entirety, all of the filling matter will be allowed to exit the interior space 30, and will have substantially the same volume as the removed shoring panel. The filling matter will therefore essentially fill the vacated space formed due to removal of the shoring panel 12, between the wall of the trench 60 and the outer face of the concrete wall 74.

As shown in Figure 8, it is possible to use two or more shoring box systems (units) 10 in series, for example in a sufficiently long trench 60. This is achieved by connecting the shoring panels 12 of the two adjacent shoring box units 10, using the connection means described above with reference to Figures 6, 7a and 7b, or Figure 7c. Because the connection involves or enables relative vertical sliding between the adjacent shoring panels 12 of the two shoring box units 10, the two shoring box units can be at different elevations to each other, as shown in Figure 8. Accordingly, shoring box units 10, according to the present embodiment of the invention, may be suitable for use in a trench 60 having uneven or sloped floors.

It will be appreciated that advantages of the present invention, at least embodiments thereof, are as follows:

• the components of the shoring box system 10 can be assembled and disassembled within the trench 60 itself, rather than this having to be done outside the trench;

• the props 22 (in particular, the lower props) can be easily removed after the concrete floor 68 is cast, to enable pouring of the walls 74 within the trench 60; removal of the upper props can be left until the walls have hardened sufficiently to be able to take load;

• the tapered shape of each of the shoring panels 12 facilitates withdrawal of the panels from the trench 60 and, more particularly, from the space between the outer faces of the newly poured concrete walls 74 and walls of the trench 60;

• the closure flaps 38 allow for filling matter such as sand to be placed within the interior spaces 30 of the shoring panels 12 and for this filling matter to run out the bottom of the shoring panels as they are removed, to fill up the space vacated by the shoring panels; and

• the hollow construction of the components of the shoring box system 10 results in their being of relatively low weight such that they can, at least in preferred embodiments, be installed and removed without the use of lifting equipment such as a crane.

Although the invention is described above in relation to preferred embodiments, it will be appreciated by those skilled in the art that it is not limited to those embodiments, but may be embodied in many other forms.

Claims

1 . A shoring box system including:

a pair of shoring panels; and

2. A shoring box system according to claim 1 , wherein the prop connectors are adapted to enable the props to be detached from the shoring panels by movement of each prop at least partially laterally with respect to the longitudinal direction in which the prop extends.

3. A shoring box system according to claim 2, wherein each prop connector includes a first connector portion on a respective prop and a second connector portion on a shoring panel, the first and second connector portions being releasably attachable to each other by means of being superposed on each other and a locking element adapted for releasably interlocking the first and second connector portions.

4. A shoring box system according to any one of claims 1 to 3 wherein each shoring panel has an upright operational orientation and includes a plurality of reinforcement elements each substantially traversing the height of the panel.

5. A shoring box system according to claim 4 wherein each reinforcement element includes an I-beam.

6. A shoring box system according to claim 4 or claim 5 wherein each shoring panel includes shoring panel walls, the walls of each shoring panel at least partly defining an interior space of that shoring panel, wherein the reinforcement elements are disposed in the interior space.

7. A shoring box system according to any one claims 1 to 5 wherein each shoring panel includes shoring panel walls, and is configured such that, when the shoring panels are in said erected position, a wall of each shoring panel facing into said interior zone is non-vertical so that an upper end of the wall is disposed more inwardly relative to the interior zone than a lower end of the wall.

8. A shoring box system according to claim 6 wherein each shoring panel is configured such that, when the shoring panels are in said erected position, a wall of each shoring panel facing into said interior zone is non-vertical so that an upper end of the wall is disposed more inwardly relative to the interior zone than a lower end of the wall.

9. A shoring box system according to claim 7 or claim 8, wherein each shoring panel tapers in a downward direction.

10. A shoring box system according to any one claims 6 to 9 wherein each shoring panel has an opening to said interior space at or adjacent to a bottom extremity of the shoring panel, and includes a closure component which is movable between a closed position in which it is attached to at least one shoring panel wall of the respective shoring panel and extends over, and thereby substantially closes, the opening to the interior space of that panel, and an open position in which the opening is substantially uncovered by the closure component

1 1 . A shoring box system according to claim 10, wherein the closure component is rotatably attached to the at least one shoring panel wall so as to be movable between said closed and open positions by rotation relative to the at least one panel wall.

12. A shoring box system according to claim 1 1 , wherein the closure component is adapted to fall from its closed position to its open position under the effect of gravity.

13. A shoring box system according to any one of claims 6 to 12, wherein each shoring panel includes a first panel wall, and a second panel wall spaced from, and opposed to, the first panel wall, one of the first and second panel walls having a lower edge which is lower than a lower edge of the other of the first and second panel walls such that the bottom of the panel is substantially wedge-shaped.

14. A shoring box system according to claim 13, wherein said other panel wall is on the same side of the panel as said interior zone.

15. A shoring box system according to any one of the preceding claims wherein the pair of shoring panels and the props attached thereto together constitute a shoring panel unit, the unit being adapted for releasable connection to an adjacent said unit.

16. A shoring box system according to claim 15, wherein each unit is adapted for such releasable connection to two adjacent units, one on each of two opposite sides thereof, so that said units together constitute a series of units.

17. A shoring box system according to claim 15 or claim 16, wherein the adjacent units are adapted for said releasable connection by means of a connection element which is slidably engageable with at least one of the adjacent units.

18. A shoring box system according to claim 17, wherein said at least one of the adjacent units defines an upwardly extending slot, the connection element being slidably receivable in the slot.

19. A shoring box system according to claim 17, wherein each of said adjacent units defines an upwardly extending slot, the connection element being slidably receivable in the slots. 20. A method of using a shoring box system according to any one of claims 1 to 19, to reinforce a ground cavity having opposing cavity walls, the method including:

20.1 disposing, in the cavity, shoring panels of the shoring box system such that the shoring panels abut two respective said opposing cavity walls; and

20.2 attaching said props to the shoring panels to maintain the panels in said erected position.

21 . A method according to claim 20 wherein step 20.2 includes attaching said props such that there is a lowermost level of props, and at least one level of props above the lowermost level, the method further including:

21 .1 after the props are so attached, pouring a concrete floor in the cavity;

21 .2 allowing the poured floor to set;

21 .3 after the poured floor has set, detaching the props in said lowermost level from the shoring panels.

22. A method according to claim 21 including, after step 21 .3, building at least one wall on the floor, the wall extending above the level at which the lowermost level of props were disposed prior to said detachment.

23. A method according to any one of claims 20 to 22 including:

then removing, from the ground cavity, each shoring panel.

24. A method of using a shoring box system to reinforce a ground cavity having opposing cavity walls, the method including: disposing, in the cavity, shoring panel units according to any one of claims 15 to 18 such that the shoring panels of each unit abut two respective said opposing cavity walls, wherein each pair of adjacent panels of adjacent units are interconnected to each other by a said connection element.

25. A shoring box system including:

a pair of shoring panels each having shoring panel walls, the walls of each shoring panel defining at least part of an interior space of that shoring panel, each shoring panel having an opening to that interior space at or adjacent to a bottom extremity of the shoring panel; and

26. A shoring box system according to claim 25 wherein each shoring panel further includes a closure component which is movable between a closed position in which it is attached to at least one shoring panel wall of the respective shoring panel, and extends over, and thereby substantially closes, the opening to the interior space of that panel, and an open position in which the opening is substantially uncovered by the closure component.

27. A shoring box system including:

28. shoring box system according to claim 27 wherein each shoring panel tapers in a downward direction.