METHOD OF INSTALLING A MODULAR BUND SYSTEM

The present invention relates to a modular bund system, and a method of installing a modular bund system. The modular bund system is suitable for installation around liquid storage tanks, pipes and machinery. The present invention is particularly suitable for raising the height of a pre-existing bund.

Bunds, alternatively known as liquid containment structures, dykes or liquid barriers, are well- known in the art. Bunds are provided around liquid storage containers, machinery, liquid carrying pipes or the like and are used to contain any unintentional liquid spillage. The bund may be formed as a low wall from brickwork or concrete. Alternatively, the bund may be modular, and be formed from pre-fabricated sections.

US 2013/0017018 A1 , CA 2,793,597 A1 and CA 2,770,163 A1 all disclose such modular systems for forming bunds and the like. All of the systems disclose the use of modular wall sections which can be joined together to form the perimeter wall of the bund. The wall sections can be flexible to enable corners to be formed, or alternatively specific corner sections can be provided. These systems disclose the use of support portions, or foot portions, which are used to provide structural support to the wall sections. The foot portions all extend from the wall portions to the interior of the bund, and in the case of US 2013/0017018 A1 and CA 2,770,163 A1 , inevitably result in gaps between the bottom edge of the wall and the surface on which the wall is supported. In addition, all of the systems require an additional liner provided within the completed perimeter wall of the bund to form the liquid barrier. There are disadvantages with the modular bund systems known in the art, and in particular the requirement for an additional liner to be provided increases the complexity of the system, and makes it difficult if not impossible to retro-fit the modular system to existing infrastructure. In addition, the configuration of the foot or support portions of the known modular systems makes it difficult to use the known systems to extend the height of existing bunds.

Thus, it would be desirable to provide a modular bund system which does not require the use of a liner to provide a liquid containment barrier. It would also be desirable to provide a modular bund system which can more easily be used to extend the height of an existing bund. According to one aspect of the present invention there is provided, a modular bund system which comprises: a plurality of wall members, each wall member comprising a foot portion; a plurality of angular connecting members, each angular connecting member configured to connect one of the plurality of wall members to another one of the plurality of wall members to form a corner of the bund. Each connecting member comprises a first flange configured to overlap an end portion of the one of a plurality of wall members, and a second flange configured to overlap an end portion of the another one of the plurality of wall members. The modular bund system further comprises means for sealing each flange to the respective wall member end portion such that a liquid impermeable bund is formed.

Advantageously, providing such a modular bund system enables a substantially liquid impermeable bund to be provided which is easy to install around existing infrastructure, including being installed to raise the height of an existing bund, and does not require the use of an additional liner.

As used herein, the term "bund" connotes a liquid containment structure, such as a liquid impermeable wall or barrier, designed to contain leaks, spillages or the like from liquid storage tanks, pipes or machinery. Each foot portion preferably extends substantially along the whole length of the respective wall member, such that, in situ, there are no substantial gaps between the bottom edge of the wall member and the surface on which the wall member is supported. In addition to the advantage of reducing the gaps between the wall and the support surface, providing such a continuous foot portion allows the wall member to be more easily cut to length as required during installation.

In a preferred embodiment, the foot portion extends from an outer face of the wall member. As will be appreciated, the foot portion preferably only extends from the outer face of the wall member, and so does not extend from the inner face. An L-shaped cross-sectional profile of the wall member and foot portion is preferably provided. Advantageously, providing such a foot portion enables the modular bund system to be used to extend the height of an existing bund more easily. Thus, the wall member may be installed such that the inner surface of the wall member is substantially coplanar with the inner surface of the existing bund wall. Providing the modular bund system in this way may reduce the risk of a leak path between the existing bund and the modular bund system of the present invention. Preferably, each foot portion comprises at least one through hole for receiving a fixing for attaching the respective wall member to a support surface. Providing such through holes enables the modular bund system to be affixed to the support surface more easily. As used herein, the term fixing connotes mechanical fixings such as bolts, screws, rivets or the like.

The modular bund system preferably further comprises at least one linear connecting member, each linear connecting member is configured to connect one of the plurality of wall members to another one of the plurality of wall members, such that inner surfaces of said wall members are substantially coplanar.

Advantageously, providing such linear connecting members allows the modular bund system to have standard lengths for the wall members, while enabling those standard length wall members to be connected together by the linear connecting member to extend the length of a side of the bund.

The or each linear connecting member is preferably configured to overlap an end portion of the one of a plurality of wall members, and to overlap an end portion of the another one of the plurality of wall members. The overlapping portion enables an improved seal between the wall members to be provided, and increases the structural rigidity in the region of the join between the wall members.

In the embodiment of the modular bund system comprising at least one linear connecting member, the system preferably further comprises means for sealing the or each linear connecting member to the respective wall member end portion.

In addition, the or each linear connecting member preferably has an L-shaped cross-sectional profile. The L-shaped cross-sectional profile preferably matches the cross-sectional profile of the wall member and foot portion cross-sectional profile.

The or each linear connecting member may further comprise at least one through hole configured such that, in situ, the or each through hole is substantially aligned with a respective through hole in a foot portion. The or each linear connecting member may comprise two or more through holes arranged such that a first one of the through holes aligns with a respective through hole in a foot portion of a first wall member, and such that a second one of the through holes aligns with a respective through hole in a foot portion of a second wall member. Aptly, the or each linear connecting member may be an integral part of a wall member prior to installation, such as by casting or welding or the like, or may be separate to the wall members prior to installation and attachable to two adjacent wall members by suitable mechanical fasteners to connect the same together.

In a preferred embodiment, each angular connecting member further comprises a central portion, wherein an inner surface of the central portion is configured to be substantially coplanar with respective inner surfaces of the one and the another one of the plurality of wall members when the first flange and the second flange overlap the respective end portions of the said wall members.

Advantageously, providing such a central portion enables the wall members to be connected and installed more easily, and enables an improved liquid impermeable seal to be provided in the corners of the bund. As will be appreciated, providing the central portion removes the requirement for a three way seal between the two wall members and the support surface which would otherwise occur at the internal corner of the bund. Removing this three-way seal enables the liquid impermeable bund to be provided more easily, and further aids in removing the need for an additional liner within the bund walls.

Each angular connecting member preferably further comprises a foot portion, which preferably extends from at least one outer face of the angular connecting member. In situ, the angular connecting member foot portion is configured to be coplanar with the foot portions of adjacent wall member foot portions.

Each angular connecting member preferably further comprises a third flange configured to overlap an end portion of the one of a plurality of wall member foot portions, and a fourth flange configured to overlap an end portion of the another one of the plurality of wall member foot portions. The additional flanges enable a yet further improvement to the seal between the angular connecting member and the wall members.

As will be appreciated, in the embodiment where the angular connecting member comprises a foot portion, the third flange and the fourth flange preferably extend from, and are offset from the foot portion. In the embodiment comprising third and fourth flanges, the third flange and the fourth flange, preferably each comprise at least one through hole configured such that, in situ, the or each through hole is substantially aligned with a respective through hole in a foot portion. Preferably, the first flange and the third flange are continuous, such that an edge of the first flange is connected to an edge of the third flange. Similarly, preferably, the second flange and the fourth flange are continuous, such that an edge of the second flange is connected to an edge of the fourth flange. Each angular connecting member preferably enables a corner having an internal angle of substantially 90 degrees to be formed. However, the angular connecting members may be formed to enable corners having other internal angles as required, such as 30 degrees, 45 degrees or 60 degrees. Preferably, each flange of each angular connecting member is at least partially lined with a polymer material. The polymer material may be a rubber, such as a synthetic rubber, which may be a foamed rubber. In a particularly preferred embodiment the polymer material is EPDM rubber (ethylene propylene diene monomer (M-class) rubber). The EPDM rubber may be full- cell or semi-cell foamed rubber. As will be appreciated, any suitable polymer material may be used in dependence on the application of the modular bund system. For example, where a particular chemical, such as an acid, is to be contained, a material suitable for use with that chemical may be used. An elastomeric sealant, such as Rallithane™ or the like may also be used. Each of the wall member, angular connecting member, and, where present, the linear connecting member, may be made from any suitable material, and in particular may be made from Glass Reinforced Plastic (GRP). The specific formulation of GRP may be chosen in dependence on the type of liquid to be contained, and in particular where a particular chemical, such as an acid, is to be contained, a GRP formulation suitable for use with that chemical may be used.

The wall members may be provided in any length, and preferably the system comprises a plurality of wall members having a first length and a plurality of wall members having a second length. For example, the wall members may be between about 400 mm and about 2000 mm, or preferably between about 800 mm and about 1600 mm. In one particularly preferred embodiment, the wall members are approximately 1400 mm in length. The wall members may be provided in any height. Preferably, the height of the wall member is between about 200 mm and about 2000 mm, and more preferably between about 250 mm and about 1250 mm. In one particularly preferred embodiment, the wall members have a height of approximately 300 mm. In another embodiment, the wall members have a height of approximately 120 mm.

Aptly, the length of a relatively high wall member may be less than other wall members in the system to allow for ease of manual handling, installation and transportation. For example, a wall member having a height of about around 1600 mm may have a length of about around 1000 mm whereas the majority of other wall members may have a height of about around 1200 mm and a length of about around 1400 mm.

The foot portion of each wall member preferably has a width between about 100 mm and about 750 mm, and more preferably between about 125 mm and about 175 mm. In one particularly preferred embodiment, the foot portion has a width of approximately 150 mm.

The flanges are preferably configured such that they overlap the respective end portions by between about 50 mm and about 150 mm, and more preferably between about 75 mm and about 125 mm. In one particularly preferred embodiment, the flanges overlap the respective end portions by approximately 100 mm.

The modular bund system preferably further comprises means for sealing each foot portion to a support surface, such that a substantially continuous seal is provided between the formed bund and the support surface. The foot portion sealing means preferably comprises a layer of polymer material provided adjacent a side of each foot portion, wherein the wall member extends from the opposing side of the foot portion. The layer of polymer material may be affixed to the face of the foot portion. Affixing the polymer material to the foot portion enables easier installation. During installation, where fixings are used to retain the wall members and/or connecting members in place, the fixings are preferably used to compress the layer of polymer material to improve the seal between the layer of polymer material and the support surface, and the layer of polymer material and the foot portion of the wall member.

Again, the polymer material may be a rubber, such as a synthetic rubber, and may be a foamed rubber. In a particularly preferred embodiment the polymer material is EPDM rubber (ethylene propylene diene monomer (M-class) rubber). The EPDM rubber may be full-cell or semi-cell foamed rubber. As will be appreciated, any suitable polymer material may be used in dependence on the application of the modular bund system. For example, where a particular chemical, such as an acid, is to be contained, a material suitable for use with that chemical may be used. An elastomeric sealant, such as Rallithane™ or the like may also be used.

The foot portion sealing means may further comprise sealant configured to be applied to inner and outer edges of the polymer material layer. The layer of polymer material may have a width less than the width of the corresponding foot portion to enable the sealant to be providing in the cavity formed between the foot portion, the edge of the layer of polymer material and the support surface. Each end portion of each wall member may be configured to receive sealant, to form a seal between two abutting wall members. The end portion may be filleted, or chamfered, such that a cavity is provided to receive the sealant. The sealant may be a mastic sealant.

Similarly, the interface between the wall member and the foot portion may be filleted, or chamfered, to provide a cavity to receive a sealant.

Each wall member preferably comprises at least one stiffening member, each stiffening member having a first edge connected to an outer face of the wall member, and a second edge connected to the foot portion. Preferably, stiffening members are provided at regular intervals along the length of the wall member. The intervals are determined in dependence on the height of the wall members to ensure that the maximum moment applied to each stiffening member does not exceed the capacity of each stiffening member, or the capacity of the wall member.

In one embodiment of the present invention, the modular bund system further comprises at least one support bracket configured to connect the foot portion of a wall member to the support surface. Such a support bracket is of particular utility when the modular bund system is used to extend the height of an existing bund, where the existing bund has a narrow width compared to the required additional height of the bund. The at least one support bracket preferably comprises through holes configured to substantially align with corresponding through holes in the foot portion for receiving fixings. The support bracket is configured to be affixed to the support surface, preferably using fixings provided through holes in the support bracket. The support bracket preferably comprises a slot configured to engage around a, where present, stiffening member. In one preferred embodiment, the linear connecting member is configured to be used as a support bracket. In one particularly preferred embodiment, the linear connecting member and the support bracket are interchangeable, such that a support bracket may be used in place of a linear connecting member, or vice-versa. By providing a modular bund system having interchangeable parts, the total number of parts required for the system may be minimised, thus reducing costs and complexity. As described herein, the present modular-bund system does not require a liner to enable a substantially liquid impermeable bund to be formed. However, the present system may comprise a liner where required, for example when forming a primary bund suitable for containing particularly difficult to contain liquids, such as strong acids or the like. The liner may be line the entire inner surface of the bund, and extend to the top of each wall member forming the bund. The liner may be mechanically affixed to each wall member, or alternatively, the liner may be chemically affixed to each wall member. The mechanical fixing may be an adhesive, or a fixing bracket configured to affix the liner to the free edge of each wall member. The liner may be applied as a layer of material, or be applied by painting, or spraying a layer of paint. The liner material may be a poly-urea, an epoxy resin, a polyurethane or any other similar material. The liner material is preferably chosen in dependence on the type of liquid to be contained. For example, where a particular chemical, such as an acid, is to be contained, a material suitable for use with that chemical may be used.

In an alternative embodiment, the modular bund system further comprises at least one access wall member comprising at least one door panel. Advantageously, providing an access door enables the bund to be accessed more easily, for example to conduct maintenance of the storage tank, pipes, or machinery that the bund was installed around. This is particularly advantageous where the bund was used to extend the height of an existing bund, where infrastructure, such as access ladders or steps, would no longer be sufficient for a user to be able to access the bund.

In this alternative embodiment, the or each access wall member further comprises at least one U-shaped frame in which the door panel is retained. The frame may further comprise channels in opposing sides of the frame into which the door panel is slidably engaged. The door panel may comprise at least one guide fin extending from the edges of the panel, in the plane of the panel, to engage slidably with the channels in the access wall member frame.

In a further alternative embodiment, the modular bund system further comprises at least one drainage wall member comprising one or more non-return valves configured to allow an outward flow of liquid from within the bund. As will be appreciated, the modular bund system, especially in the alternative embodiments, may be used for flood defence to prevent the ingress of liquid, such as water into an area protected by the bund. In a further embodiment, the modular bund system further comprises at least one sump wall member. The sump wall member comprises a liquid collection tank and a plurality of walls extending from the tank to form at least a portion of a modular bund. The sump wall member is preferably configured such that it can be positioned outside of the footprint of the formed bund. The liquid collection tank is preferably substantially rectangular. In this embodiment, the sump wall member comprises three walls each extending respectively from three walls of the tank. In this way, one wall of the tank is open to the interior of a formed bund.

The sump wall member preferably further comprises a threshold portion, configured to extend outwardly from the tank and between at least two of the said plurality of walls. The threshold is configured to extend from the wall of the tank open to the interior of a formed bund. The threshold is preferably configured to be sealed to the support surface on which the bund is formed. The seal may be a layer of polymer material as described above. The base liquid collection tank is preferably configured to lie below the level of the support surface on which the bund is formed.

The or each of the said plurality of walls are preferably configured to be connected to a wall member or an angular connecting member and are further configured such that the said walls extend passed a wall of the tank. Where present, the threshold is preferably further configured to extend between the extended walls. More preferably, the threshold extends further than the extended walls.

At least one of the extended walls preferably comprises a corner portion configure such that a first portion of the or each extended wall is substantially perpendicular to a second portion of the or each extended wall. Thus, the sump wall member is configured to expand the footprint of a formed bund.

In a preferred embodiment, the sump wall member further comprises at least one foot portion configured to extend outwardly from the tank at the junction between the tank and the said plurality of walls. The sump wall member may comprise at least one stiffening member extending between the foot portion and at least one of the plurality of walls. The sump wall member may further comprise a pump configured to pump liquid substantially from the bottom of the settling tank. The sump wall member is preferably used where oil leaks may be expected, and where the bund is open to the atmosphere and thus may collect rain water and the like. The pump may therefore be configured to pump liquid water from the bottom of the tank, to separate the collected oil for later disposal. The sump wall member may further comprise an oil separator.

In one embodiment, the liquid collection tank is substantially rectangular having a width of between about 800 mm and about 1000 mm, more preferably between about 850 mm and about 950 mm and in a particularly preferred embodiment about 900 mm, and a length of between about 500 mm and about 700 mm, more preferably between about 550 mm and about 650 mm, and in a particularly preferred embodiment about 600 mm. The liquid collection tank preferably has a depth of between about 500 mm and about 700 mm, more preferably between about 550 mm and about 650 mm, and in a particularly preferred embodiment about 600 mm. The dimensions of the walls and, where present, the foot portions are preferably the same as the dimensions of the corresponding wall members. The threshold preferably has a width between about 1 .5 times and about 3 times the width of the foot portion, more preferably between about 1 .75 times and about 2.25 times, and in a particularly preferred embodiment about 2 times.

According to a further aspect of the present invention, there is provided a method of installing a modular bund system as described herein. The method comprises the steps of: locating one of the plurality of wall members on a support surface; locating on the support surface another one of the plurality of wall members; locating on the support surface an angular connecting member between the one and the another one of the plurality of wall members such that the first flange overlaps an end portion of the one of the plurality of wall members and the second flange overlaps an end portion of the another one of the plurality of wall members; locating further ones of the plurality of wall members and further angular connecting members on the support surface so as to form a continuous bund; and sealing the joints between each flange and each respective wall member to form a liquid impermeable bund.

Preferably, the method further comprises the step of aligning each wall member such that each flange is substantially parallel to a respective end portion of the wall member.

Preferably, the method further comprises the step of locating a linear connecting member such that the linear connecting member overlaps an end portion of one of the plurality of wall members and another one of the plurality of wall members so as to connect the said wall members. The method preferably further comprises the step of sealing the joints between the linear connecting member and the wall members, and sealing the joint between the two said wall members.

Preferably, the method further comprises the step of locating a layer of polymer material on the surface on which the modular bund system is to be installed, and may comprise the step of applying a sealant to seal the layer of polymer material to the support surface. The method may further comprises the step of applying a sealant at the interface between each wall member foot portion and the support surface, and/or applying a sealant to all joints within the modular bund system.

The method may further comprise the step of fixing the modular bund system to the support surface. The modular bund system may be fixed to the support surface using fixings provided in the through holes.

In a particularly preferred embodiment, the method further comprises the step of cutting at least one of said wall members to a desired length. Enabling the wall members to be cut to length provides a system which can be used to form a bund of any required size without providing specific, and therefore costly and time consuming, sized parts.

The method may comprise installing the modular bund system on a pre-existing bund. In this embodiment, the method may comprise the step of aligning the inner surface of each wall member and the inner surface of the pre-existing bund such that the said inner surfaces are substantially coplanar.

The various members of the modular bund system may be formed in a mould, and preferably the mould is provided with a rough surface, such that the one side of each member is provided with a relatively rough surface as compared to the other side of the member. During the moulding process, one side of each member is exposed and may be finished with a relatively smooth surface as compared to the other side of the member.

In addition, each member may be formed in any appropriate colour, and for example, the member may be white, yellow, or red. Advantageously, the modular bund system members are preferably formed in a colour which would enable a person to immediately be aware of the potential trip hazard that the bund might present. The modular bund system may be installed such that the foot portion is provided inside the bund or outside the bund. Advantageously, providing the modular bund system members with a first side having a relatively smooth surface and a second side having a relatively rough surface, enables the system to be installed in dependence on the requirements of the bund. For example, when the bund may need to be washed down during use, for example when containing liquids such as oil, preferably the relatively smooth surface is provided on the inside of the bund. However, where the bund may be coated, such as with a spray coating, the relatively rough surface may be provided on the inside to improve the bond between the bund members and the coating.

In addition, the outer side of the foot portion to be supported on the support surface may also be relatively rough. The relatively rough side may advantageously enable an improved seal to be formed between the member and the support surface using a sealant applied between the member and the support surface.

Any feature in one aspect of the invention may be applied to other aspects of the invention, in any appropriate combination. In particular, method aspects may be applied to apparatus aspects, and vice versa. Furthermore, any, some and/or all features in one aspect can be applied to any, some and/or all features in any other aspect, in any appropriate combination.

It should also be appreciated that particular combinations of the various features described and defined in any aspects of the invention can be implemented and/or supplied and/or used independently.

The invention will be further described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 shows an isometric view of an installed modular bund system according to the present invention;

Figure 2 shows a cross sectional area view of a wall member of the modular bund system;

Figure 3 shows an isometric view of a portion of the modular bund system showing attachment of connecting elements;

Figure 4 shows a side view of a wall member of the modular bund system; Figure 5 shows a side view of an angular connecting member of the modular bund system;

Figure 6 shows an isometric view of an angular connecting member of the modular bund system;

Figure 7 shows an expanded top view of a corner of the modular bund system;

Figure 8 shows an alternative angular connecting member of the modular bund system;

Figure 9 shows an isometric view of the inner face of a linear connecting member of the modular bund system;

Figure 10 shows an isometric view of a bolt securing angular connecting members via through holes;

Figures 1 1 show further views of the secured angular connecting members of Figure 10; Figure 12 shows an isometric view of a linear connecting member in use;

Figures 13 show a support bracket used to reinforce the wall member;

Figure 14 shows an alternative wall member comprising an access panel; Figure 15 shows the door panel of the access wall member shown in Figure 14;

Figure 16 shows a detailed view of a support bracket used to support the modular bund system;

Figure 17 shows an isometric view of the modular bund system including a drainage wall member;

Figure 18 shows a sump wall member of the modular bund system; Figure 19 shows a further view of the sump wall member of Figure 18; and

Figures 20a and 20b show a split-collar arrangement for passing a cable or pipe through a wall member of a modular bund system according to certain embodiments of the present invention. A modular bund system 100 installed to raise an existing bund 102 is shown in Figure 1 . However, as will be appreciated, the modular bund system 100 may also be installed as a primary bund. The modular bund comprises wall members 104, angular corner connecting members 106 and linear connecting members 108, to form a barrier substantially impermeable to liquid.

The modular bund system 100 has a generally square or rectangular configuration provided by straight wall members 104 extending between the corner 106, or linear 108 connecting members. These elements are secured together using a sealant and affixed atop a surface, 102, as explained further below.

The wall members 104 are arranged to be connected in series with one another to form a perimeter wall of the bund system 100. The wall members 104 are preferably formed of glass reinforced plastic (GRP) and have an L-shaped cross sectional profile as shown in Figure 2. The upper portion of each wall member 104 is a flat, rectangular sheet of GRP. This upper portion provides substantially flat inner 1 12 and outer 1 14 faces, as shown in Figure 1 . The lower portion of the L-shaped cross sectional profile is a foot portion 1 16 extending from the lower edge of the outer face 1 14 to provide support to the wall member 104 when installed in situ. Each foot portion 1 16 also provides a surface with which to secure the modular bund system 100 to the underlying surface, or bund 102, as shown in Figure 3.

Additional support of the wall members is provided by stiffening members 1 18, each comprising a first edge 200 connected to the outer face 1 14 of a wall member 104, and a second edge 202 connecting to an upper face of the foot portion 1 16. The stiffening members 1 18 are preferably triangular and stand substantially perpendicular to the foot portion 1 16. Each wall member 104 may be provided with one or a plurality of stiffening members 1 18, as shown in Figure 4, in dependence on the length and height of the wall member, and the width of the foot portion. The wall members 104 are connected via the corner 106 and linear 108 connecting members. The corner connecting member 106 enables two wall members to be connected together at an angle, preferably at 90 degrees, as can be seen in Figure 1 . In this configuration the wall members 104 are not in contact with each other, but a substantially flat inner surface is provided between the corner member 106 and each wall member 104. That is to say, the inner surface of the wall member and the inner surface of the corner member are substantially coplanar. To enable the inner surface to be substantially coplanar, the corner connecting member 106 firstly comprises a central foot portion 500, as shown in Figure 5, which is arranged in the same plane as the foot portions 1 16 of the wall members 104 when installed. This provides a base for the modular bund system 100 when installed on substantially the same plane around the entire perimeter. In situ, upwards from this central foot portion 500 is a central portion 502, to extend between the two wall members 104 to be connected when installed, with edges in the same plane as each of these wall members 104 to provide a substantially flat inner surface, either side of the corner. Each angular connecting member 106 additionally comprises two flanges, a first flange 504 and a second flange 506. Each flange extending outwards to overlap an end portion of the wall member 104 to which it is connected when installed, as shown in Figure 3. These flanges 504, 506 are rigid and also made of GRP. As can be seen, the flanges are configured such that they extend to the top edge of the wall member when the system is installed in situ.

Each angular connecting member 106 additionally comprises a third flange 508 and a fourth flange 510 which extend outwards from the lower edges of each of the first 504 and second 506 flanges respectively. These third 508 and fourth 510 flanges are configured to overlap end portions of the foot portions 1 16 of the wall members 104 to be connected when the bund 100 is installed. As shown in Figure 6, the first 504 and second 506 flanges further comprise a layer of polymer material 600 on their inner face 602, which engages with the end portion of the wall member 104. Each layer of polymer material extends continuously from substantially the top of the respective first and second flanges around the corner formed between the first and third flanges and the second and fourth flanges to the respective edge of the third and fourth flanges. The polymer material is preferably EPDM rubber. An elastomeric sealant, such as Rallithane™ or the like may also be used. Figure 7 shows an expanded plan view of the corner connecting member 106, and two wall members 102.

Figure 8 shows an alternative corner connecting member 800 for forming an internal, as opposed to external corner of a bund which corner connecting member 106 is configured to form. The corner connecting member 800 comprises similar features to the corner connecting member 106, including a central portion 802 configured to be coplanar with the inner surface of wall members 104 to which the corner connecting member 800 is connected, first flange 804, and a second flange 806 configured to overlap end portions of the wall members 104, and a third flange 808 and a fourth flange 810 configured to overlap end portions of the foot portions with a layer of polymer material to form a seal between the corner connecting member and the wall member.

In addition to connecting two wall members to form a corner of a bund, two wall members 104 can be connected such that they are substantially coplanar using linear connecting members 108. As shown in Figure 3 and Figure 9 each linear connecting member is L-shaped and configured to overlap both the upright portion and foot portion 1 16 of each of the wall members 104 to be connected. The lower portion 900 of the linear connecting member 108 is the portion of the L-shaped linear connecting member 108 to overlap the foot portions 1 16 of the wall members 104 to be connected. The inner face 902 of the linear connecting member, where it overlaps the upright portions of the wall members 104 to be connected, is lined with a layer of polymer material 904 with which it engages with the wall members 104. Similarly to the angular connecting member, the layer of polymer material extends continuously from substantially a first edge of the linear connecting member around the corner and substantially to a second edge. Aptly, the or each linear connecting member may be an integral part of a wall member prior to installation, such as by casting or welding or the like, or may be separate to the wall members prior to installation and attachable to two adjacent wall members by suitable mechanical fasteners, such as bolts, to connect the same together. Each linear 108 or corner 106 connecting member additionally comprises through holes 906, 1000, as shown in Figure 9 and Figure 10. These through holes 906, 1000 enable the bund system 100 to be affixed to a surface, or bund 102, as shown in Figure 10. These through holes 1000 are located one in each of the third 508 and fourth 510 flanges of the angular connecting members 106, shown in Figure 10, and two 906 in the lower portion 900 of the linear connecting members 108 that overlap the foot portions 1 16 of the wall members 104 to be connected, shown in Figure 1 1 . There are corresponding through holes 1002 in the foot portions 1 16 of the wall members 104 that align with the through holes 906, 1000 in the connecting members 106, 108 when the modular bund 100 is installed. Into these through holes 906, 1000 bolts 908 or other fastening means are inserted to affix the bund system 100 to the surface, or bund 102. A layer of polymer material 1004 is provided between the wall member 104 and the support surface, and the layer of polymer material 1004 extends continuously between the corner connecting member 106 and the support surface. An elastomeric sealant, such as Rallithane™ or the like may also be used. As will be appreciated, a combination of corner 106 and linear 108 connecting means are used to connect a plurality of wall members 104 to form a modular bund system 100 of required dimensions. Figures 1 1 show side views of the corner connecting member as installed on a support surface such as an existing bund 102, as shown in isometric view in Figure 10. The corner connecting member 106 is affixed to the support surface 102 by the bolts 908. The bolts extend through the flange 508, through the foot portion 1 16 or the wall member 102, and through the layer of polymer material 1004. A sealant, such as a mastic 1 100, 1 102, may be provided to form a seal between the layer of polymer material, the support surface 102 and the wall member 104 or the corner connecting member 106. An elastomeric sealant, such as Rallithane™ or the like may be used.

Figure 12 shows two wall members 104 connected together using a linear connecting member 108. A similar joint is formed between the linear connecting member and the wall members, as with the corner connecting member and the wall members as described above with reference to Figures 10 and 1 1 .

The layer of polymer material is substantially rectangular to align under the foot portions 1 16 of the wall members 104 and angular connecting members 106 along the entire perimeter of the bund system 100 once installed. Alternatively, the polymer material layer may be affixed to the lower face of the foot portions 1 16 of the wall members and the lower face of the central foot portion 500 of the corner connecting members 106 before installation of the bund, such as during the manufacture of the system.

As shown in Figure 13(a), the modular system may further comprise a support bracket 1300. The support bracket 1300 provides additional support to a wall member of the bund 100 when assembled on top of a pre-existing bund 102. The support bracket has an L-shaped cross- sectional profile having a first portion 1302 and a second portion 1304. The first portion 1302 overlaps a foot portion 1 16 of a wall member 104. The second portion 1304 lies adjacent the outer face of the pre-existing bund. The support bracket 1300 is configured to provide structural support to the wall member when the pre-existing bund is too narrow to enable the foot portion of the wall member to be wide enough to support the wall member.

The support bracket 1300 comprises a slot 1306, as shown in Figure 13(b), for engaging around a stiffening member. In addition, the support bracket 1300 comprises through holes 1308 such that, in situ, the through holes align with the through holes 1002 in the foot portion 1 16 of the wall member 104. Advantageously, the support bracket has the same configuration as the linear connecting member, such that the linear connecting member can be used as a support bracket. In this configuration, the inner face 902 of the linear connecting member 108 is facing outwards from the modular bund system 100, while the outer face overlaps the outer wall of the existing bund 102.

Each support bracket, or where used, linear connecting member 108, may be secured to the existing bund 102 by means of a sealant, and/or using bolts 908 or alternative securing devices in through holes 1308. Where the linear connecting member is used as a support bracket, the slot may be provided during installation.

In one embodiment of the present invention, the modular bund system 100, of Figure 14, includes at least one access wall member 1400, in place of a standard wall member 104. Each access wall member 1400 includes a U-shaped frame 1402 extending from the top edge. This frame 1402 can vary in size, extending part of the way down the access wall member 1400 and part of the way across it, or extending substantially the whole way down and across the access wall member 1400. This frame 1402 comprises channels 1404 in the opposing vertical sides and bottom side, into which a door panel can slide. As shown in Figure 15, the door panel 1500 is substantially square or rectangular in order to fit within the frame 1402, providing a barrier impermeable to liquid when installed within the frame 1402. The door panel 1500, as shown in Figure 15, further comprises guide fins 1502, extending from two opposing edges, and the bottom edge, which slidably engage with the channels 1404 in the frame 1402. Alternatively, the U-shaped frame 1402 may include abutment flanges located along each of the opposing vertical sides and bottom side of the frame. A swing gate (not shown) may hingedly attach to one of the vertical sides by one or more suitable hinges, such as barrel hinges, piano hinges and nylon sprung hinges or the like. The swing gate abuts the flanges when in a closed position. A suitable sealing member may be located on each flange to form a seal between the swing gate and the frame 1402 when the swing gate is in the closed position. A suitable sealing material may be a resilient plastics or rubber material, such as ethylene propylene diene monomer (EDPM), or the like. Such a sealing member would prevent the ingress/escape of flood water or contaminant, for example, into/out of the boundaries of the bund system 100, depending on how the swing gate was mounted to the frame 1402. Such a sealing member would also further compress when under load from flood water or contaminant acting on the swing gate. The swing gate may further include one or more securing members that engage with corresponding apertures in the frame for securely attaching the swing gate to the frame in a closed position. Suitable securing members may include one or more mechanical fasteners, such as bolts, located around a bottom region of the swing gate and vertical edge of the swing gate which is opposite to the hinged edge. Alternatively, the securing members may each be a hand- rotatable securing member that includes a handle on an outer side of the swing gate and a rotatable locking portion located on an inner side of the swing gate that is insertabie into a corresponding aperture of the frame 402 when in a first position and which cannot be removed from the aperture when rotated into a second position thereby to securely lock the swing gate in the closed position. Such rotatable securing members could be used to securely lock the siidable door panel 1500 described above in a closed position relative to the frame 1402. Alternatively, instead of being insertabie in a corresponding aperture in the frame 1402, each rotatable locking member may engage with a rear face of a corresponding flange to securely lock the swing gate or door panel in a closed position relative to the frame.

The modular bund system 100 may be constructed such that the inner face of the modular bund system and the outer face of a support surface in the form of, for example, a concrete slab 1600, are substantially coplanar. This embodiment requires a base bracket 1602 to be secured to the outer wall of the slab 1600 upon which the modular bund system 100 may be assembled, as shown in Figure 16.

Each base bracket 1602 preferably has an L-shaped cross sectional profile and a first face 1604 to engage with the outer wall of the slab 1600. The first face 1604 comprises at least one through hole configured that, in situ, a bolt or alternative securing device may be used to secure the base bracket 1602 to the outer wall of the slab 1600 such that a second face 1606 of the base bracket is coplanar with the top of the slab 1600.

The second face 1606 of each base bracket 1602, in situ, provides a support surface upon which to assemble a modular bund system 100, as described above. The second face 1606 of each base bracket 1602 may further comprise at least one through hole configured such that, in situ, said through hole aligns with through holes in the foot portion 1 16 of the wall members 104, or access wall members 1400, and connecting members 106, 108 of the modular bund system 100. When assembled, bolts or alternative securing devices may be used to secure the base bracket 1602 to the modular bund system 100.

As shown in Figure 17, in one embodiment of the present invention, the modular bund system 100 includes at least one drainage wall member 1700, in place of a standard wall member 104. Each of these drainage wall members 1700 includes a non-return valve 1702 configured to allow the outflow of liquid from within a formed bund 100 when in use. Such a wall member allows the system to be used as a flood defence system. In certain embodiments of the present invention, a sump may be provided inside the general perimeter of the bund system, e.g. incorporated into a concrete slab on which the bund system is installed. In an alternative embodiment it may be advantageous for the modular bund system to include an external sump to collect and remove liquid contained within the bund. Figures 18 and 19 show one example of such an external sump which is located outside the boundaries of the slab 1818. The sump wall member 1800 comprises a liquid collection tank 1802, three walls 1804, 1806 and 1808 extending from the tank, and a foot portion 1810. As can be seen, the liquid collection tank is substantially rectangular, and the three walls 1804, 1806 and 1808 extend from the three respective sides of the tank, leaving one side of the tank open to receive liquid from within the formed bund.

Two of the walls 1804 and 1808, extend past the side of the liquid collection tank 1802, and are each provided with a corner section 1810 and 1812, which enable the end portions of the walls 1804 and 1808 to be connected either to wall members 104, or to angular connecting members 106, as shown in Figure 19. The corner sections enable the sump wall member to be provided such that the liquid collection tank lies outside of the main footprint of the formed bund. As will be appreciated, where the sump wall member is connected to a wall member 104, a linear connecting member 108 is used to form the joint, as described above.

The sump wall member 1800 is further provided with a threshold 1814 which extends from the top edge of the liquid collection tank wall 1816 which does not have a wall. The threshold extends between the walls 1804 and 1808, and as can be seen, extends further into the interior of the formed bund than the walls 1804 and 1808, and has a maximum width such that the outer edge extends to outer edge of the foot portion 1810. The threshold 1814 is substantially perpendicular to the tank wall 1816. As will be appreciated, the provision of the threshold enables a continuous surface to be provided from the support surface to the tank 1802. The sump wall member is particularly advantageous where the modular bund system is provided on a slab 1818, such as a concrete slab used as a foundation for machinery which may leak oil, or the like. By using the sump wall member, the concrete slab need not be broken up to accommodate the sump, as would be required to provide a conventional sump, and thus enables the sump to be installed more easily and cheaply.

The liquid collection tank 1802 is provided with a supporting surface 1820 around the perimeter of the tank to enable a grill 1900 to be provided. The grill 1822 prevents large debris from entering the tank and as a safety feature to prevent personnel from falling in. The liquid collection tank is provided with a pump 1902 to enable the collected liquid to be pumped out of the liquid collection tank 1802. Where the sump wall member is used to collect both oil run off, and rain water, the pump is configured with an inlet adjacent the base of the tank such that only the rain water is pumped out, leaving the oil within the tank for later appropriate disposal. The pump 1902 may be connected to mains electricity or may be connected to a renewable source of electrical energy such as a solar cell and/or wind turbine, or the like.

Similarly to the above described members of the modular bund system, the sump wall member 1800 may be metal, such as steel, or preferably made from GRP. The grill 1822 may be metal, such as steel, or preferably made from GRP.

The sump wall member 1800 may be pre-fabricated, e.g. by welding, to provide a one-piece sump system that is lowered into a pre-formed hole sized to receive the liquid collection tank 1802 and then connected to wall members of the modular bud system by suitable connecting members 108 according to certain embodiments of the present invention. Alternatively, the three wall members 1804,1806,1808, corner sections 1810,1812 and foot portion 1810 may be pre-fabricated, e.g. by welding, to form a one-piece bund sump wall portion for locating on and attaching to a flanged lip of the liquid collection tank 1802. Bolts may be used to attach the corresponding flanges together and sealant may be provided therebetween. Further alternatively, the sump wall may be formed by using corner connecting members, and optionally linear connecting members, to connect wall members together in accordance with certain embodiments of the present invention as described above. The sump wall members may also include stiffening portions like the modular bund wall members described above and shown for example in Figure 1 .

The sump wall member 1800 is installed in a similar method to the wall members 104, as described below. The threshold 1814, and where provided on a solid support surface, the foot portion 1810 are provided with a layer of polymer material between the threshold, or foot portion, and the support surface, such as the slab 1818.ln order to form a liquid impermeable bund, the modular bund system 100, once installed, is applied with a sealant along all joints and along the base. This sealant is a mastic to provide a liquid impermeable seal across the whole system. The mastic is applied along the joints between the connection members 106, 108 and the wall members 104. In the case of linear connecting means 108 connecting the wall members 104 such that they are substantially coplanar, there is also sealant applied between the abutting wall members edges. The mastic sealant is applied along the edges of the polymer material layer to seal it to the surface, or bund 102, and further applied once the bund system is installed to form a liquid impermeable seal along the entire base of the bund system. The mastic may also be applied to the overlapping portions of the wall members 104 and connecting members 106, 108 before installation to seal these elements together. Where the modular bund system members are installed such that the foot portions are inside the bund, the adjacent members to the sump wall member are provided on the other side of the end portions of the walls 1804 and 1808. As can be seen, the additional width of the threshold enables the linear connecting member to form a seal between the threshold and the adjacent wall member. In this case, the sump wall member may be positioned at a distance from the edge of the slab 1818, such that the external surface of the formed bund is adjacent the edge of the slab 1818.

During installation, a first wall member 104 is positioned on a polymer layer, with the foot portion 1 16 overlapping the polymer layer. For a corner of the modular bund system to be installed, an angular corner member 106 is positioned adjacent to this first wall member 104. One of the third 508 or fourth 510 flanges is positioned overlapping a portion of the foot portion 1 16 of the wall member 104. The first 504 or second 506 flange is positioned to overlap the outer face 1 14 of the upper portion of the wall member 104. The central foot portion 500 is positioned to lie on the polymer layer, abutting the edge of the foot portion 1 16 of the wall member 104 to which it is connected. The central portion 500 is positioned abutting the edge of the upper portion of the wall member 104 to which it is connected. The polymer layer 600 on the first 504 or second 506 flange engages with the wall member 104. The sealing mastic may be applied to this polymer layer or the inner face of the flange, to enhance the adhesion of the connection. To further seal the joint between the wall member 104 and the angular connecting member 106, the sealing mastic is applied along the edges of the joint. To secure this portion of the modular bund system to the surface or previous bund 102, the sealing mastic is further applied along the joint between the base of the modular bund system and the surface or previous bund 102.

The foot portions of the wall members are secured to the support surface using fixings, such as bolts. Where the flanges overlap the foot portions, fixings, such as bolts, are used to secure the flange both to the foot portion and the support surface.

To lengthen a side of the modular bund system, two wall members 104 may be connected substantially coplanar to each other using a linear connecting member 108. With a first wall member 104 secured into the bund, a second wall member 104 is positioned substantially coplanar to it, with adjacent edges 146 of the foot portions 1 16 and the upper wall member 104 abutting. The linear connecting member 108 is then positioned across the joint. The lower portion of the linear connecting member 108 overlaps portions of the foot portions 1 16 of the wall members 104 to be connected. The inner face of the linear connecting member 104 overlaps portions of the outer faces 1 14 of the upper portions of the abutting wall members 104. The polymer layers on the inner face of the linear connecting member 104 engage with the wall members 104. The sealing mastic may be applied to this polymer layer or the inner face of the linear connecting member 108, to enhance the adhesion of the connection. To further seal the joint between the wall members 104 and the linear connecting member 108, the sealing mastic is applied along the edges of the joint. To secure this portion of the modular bund system to the surface or previous bund 102, the sealing mastic is further applied along the joint between the base of the modular bund system and the surface or previous bund 102.

This process is repeated along the perimeter of the previous bund 102 or area of the surface to be bunded to install the complete modular bund system. As shown in Figures 20a and 20b, one or more cables or pipes may be required to pass through the modular bund system 100. A wall member may include an aperture for passing a new or existing cable or pipe through the wall member. An existing pipe would have to be disconnected so that the disconnected end can be fed through the aperture in the wall member. A rubber grommet may be located in the aperture to protect the cable or pipe from abrading with the wall member.

Alternatively, for an existing cable or pipe 2000 which cannot be disconnected and/or is relatively large, the length of the wall members can be selectively chosen such that a join is located where the cable or pipe is. A semi-circular opening 2020 corresponding in shape with the cable or pipe 2010 can be cut on site or pre-formed in opposed edges of the adjacent wall members 2030. The adjacent wall members 2030 can then be positioned either side of the cable or pipe 2010. A grommet may be located in the formed aperture to protect the cable or pipe from the edges of the wall members. Split collar portions 2040 are then respectively placed on top and below the cable or pipe 2010 and attached by welding or mechanical fastening to the wall members. A sealant may also be used. Each split collar portion 2040 includes a vertical flange 2042 and a pair of horizontal flanges 2044 located either side of a curved flange 2046 that accommodates the cable or pipe 2010. The vertical flange 2042 is attached to the outer face 2050 of the wall member and the horizontal flanges 2044 are attached to respective horizontal flanges of the other split collar portion. The curved flange 2046 has a length parallel with the cable or pipe to provide a support surface for supporting the cable or pipe and also to reduce the amount of bend of the cable or pipe proximal the wall member and in turn minimise any localised stresses on the cable or pipe. An exit edge of the curved flange 2046 may be tapered to reduce any wear and/or localised stresses on the cable or pipe 2010. Split collar portions 2040 may be used on the inside and/or outside faces of the modular bund wall members as desired. A foot portion connecting member 2060 may be used to further connect/seal the adjacent wall members 2030. The foot portion connecting member 2060 has a vertical flange 2062 that is attached to the vertical face of each wall member and a horizontal flange 2064 that is attached to the horizontal foot portions 2016 of the wall members 2030. Again, a suitable sealant may be used between the foot connecting member 2060 and the wall members.

Certain embodiments of the present invention may therefore provide a modular bund system that is quick and easy to erect and install on a variety of surfaces, such as a concrete slab, earth, stone foundation, wall, or the like, and which can be effectively and efficiently used to contain spillages/leakages from plant equipment located inside the boundaries of the bund system and/or prevent the ingress of liquid, such as flood water, into the confines of the bund system. A modular bund system according to certain embodiments of the present invention may enable a substantially liquid impermeable bund to be provided which is easy to install around existing infrastructure, including being installed to raise the height of an existing bund, and does not require the use of an additional liner. The components of the bund system are easy to handle and install and provide significant flexibility to the installation process, such as shape of the formed bund wall and height and length of each individual wall member. The number of components is minimised to reduce cost and complexity. Pipes and cables can also be easily accommodated for and a sump may be incorporated into the system if desired.