A ground water drainage system

Abstract

 The invention relates to a ground water handling or attenuation system comprising at least two vertically stackable perforated cells 201, 202, each with an open major surface which are joined together in open-face to open-face relation by a grip 205, there being in the embodiment two grids 20t per assembly. Each cell has upstanding columns 203 of predominantly female form into which male spigots 206 of the grid(s) engage with a push fit, there being releasable locking means 208 of some spigots 206 which engage behind internal locking means of respective columns.

Description

[0001] The invention relates to a ground water system, particularly to a ground water handling or attenuation system that can deal with control or otherwise attenuate water that falls as rain, particularly in "flash" storms or from flooding, including flooding caused by melting ice and/or snow.

[0002] Modem building and agricultural methods are such that water which historically would drain away by natural seepage is no longer able to do so, which leads to floods, soil erosion and the like.

[0003] This means that often modem building and agriculture methods often means that water falling as rain or formed from melting ice or flooding cannot return to the ground to form ground water. Instead, it often flows away from a locality where it is generated, depriving the ground of its beneficial effects, and overflowing normal drainage systems, therefore leading to flooding, erosion and general disruption to the environment. Prior systems to cater for this generally have the disadvantage of being massive, and of not having sufficient capacity to provide for attenuation, by which is generally meant the lengthening of the period during which water is held at a location where it arises e.g. at a storm area, for dispersal into the ground at that area without flowing away therefrom.

[0004] It is an object of the invention to seek to mitigate these disadvantages.

[0005] According to the invention there is provided a drainage cell for a ground water handling system, comprising a body defined by perforated boundary walls, a perforated base, and an open top, there being a plurality of discrete upstanding connector members rising from the base towards the open top, and means adapted for interconnection of two cells which in use are placed with their open tops substantially parallel.

[0006] The walls may each have respective releasable interengagement means, the arrangement being such that one cell can be releasably mountable on another similar cell with respective tube members and releasable interengagement means in cooperation to provide a modular construction.

[0007] The connector members may be characterised by comprising upstanding columns, there being in a cell identical columns which are either male columns or female columns which form said interconnection means, whereby when a cell having male interconnection means is assembled open top to open top with a cell having female interconnection means, the two cells are interconnected.

[0008] The respective releasable interengagement means may comprise projecting means at one edge of one wall and respective cooperable receiving means on opposite edge of the wall, preferably the receiving means comprising sockets. The tubes may each be circular in cross-section, and the part of reduced dimension may comprise a tubular extension of less diameter than that of the tube. This provides of ease of construction as an integral member. The tubes may be connected with each other externally and/or to the walls by webs. This provides for a relatively rigid structure, particularly as the webs may be radial webs, thereby providing for symmetrical distribution of imposed loads.

[0009] The walls may be defined by spaced apart substantially parallel spacer elements extending between substantially orthogonally arranged support elements. This again provides for ease of construction, and a relatively rigid one.

[0010] The spacer elements may be substantially flat, for providing strength in the thickness of the wall. The support elements may be substantially square in cross-section. This construction again seeks to provide relative rigidity, particularly when there may be four spacer elements extending between two adjacent support elements.

[0011] The four spacer elements may comprise in use an upper pair and a lower pair of space elements.

[0012] The interconnection means may be characterised by comprising a separate device adapted for interposition between two cells having their open tops facing.

[0013] The connector members may be characterised by comprising columns each defining a male or female connector.

[0014] The separate device may be characterised by comprising a grid defining a plurality of discrete female or male connection means adapted for interconnection with a respective male or female connector member of a cell.

[0015] The connector member may be male and may terminate below the height of the boundary walls.

[0016] The connection means of the device may also be female and may have a height adapted for interconnection with the male connector members whereby two cells may be interconnected with their open tops facing.

[0017] The interconnection means may also be characterised by comprising a grid adapted for interengagement with the connector members of the cell whereby to close the open top and a plurality of independent connector elements for connecting a cell and grid assembly with another cell having its open top facing the originally open top of the cell of the cell and grid assembly.

[0018] The discrete upstanding connector elements of each cell may define male connector members.

[0019] There may be means defining an inlet and/or outlet for water in at least one boundary wall.

[0020] The inlet and/or outlet may be characterised by comprising a substantially circular seating for receiving a pipe for water.

[0021] The seating may have an integral spider which is removable to define an entry for the pipe.

[0022] The cell may be integrally moulded in one piece from plastic materials, suitably being characterised by being made by injection moulding.

[0023] According to another aspect of the invention there may be provided a set of parts for assembly to form a ground water attenuation system, comprising a plurality of drainage cells as hereinbefore defined, and a plurality of separate base members, the base members and cells being assemblable to provide the system.

[0024] The base members may each comprise a plurality of seats for receiving a respective reduced dimension part of a tube.

[0025] The seats may each comprise a through hole in a web of the base.

[0026] The base may each be defined by a boundary wall upstanding from the web.

[0027] The wall may have a plurality of through passageways adjacent the web. This provides for both rigidity and drainage.

[0028] The set may include a geotexlite cover for the set, or for an individual cell of the set. This provides for additional attenuation of ground water, particularly when the cover may be water impermeable.

[0029] According to another aspect of the invention there may be provided a base for supporting a cell of a ground water attenuation system comprising a body defined by a web and boundary walls projecting therefrom, the web having a plurality of spaced apart through bores for receiving a corresponding part of a cell in use.

[0030] According to a yet further aspect of the invention there is provided a groundwater attenuation system, comprising a cell or cell assembly as hereinbefore defined.

[0031] The cell or cell assembly may be covered in a geotextile material, for example the material may be water impermeable.

[0032] Cells, systems and a base for a ground water handling or attenuation system are hereinafter described, by way of example, with reference to the accompanying drawings.

Fig. 1 is a perspective inverted (upside down) view of a pair of adjacent drainage cells according to the invention;

Fig. 2 is a perspective view from above of a base element;

Fig. 3 is a perspective view of a plurality of cells and bases assembled to form a modular ground water attenuation system.

Fig. 4 is a schematic perspective view of a first embodiment comprising two cells according to the invention, separated;

Fig. 5 is a schematic perspective view of the cells of Fig. 4, assembled;

Fig. 6 is a schematic perspective exploded view of a second embodiment according to the invention;

Fig. 7 is a schematic perspective view of the second embodiment of Fig. 6, assembled;

Fig. 8 is a perspective view, to an enlarged scale, of interconnection means of the second embodiment;

Fig. 9 is a schematic perspective view of a third embodiment;

Fig. 10 is a schematic perspective view of the third embodiment, assembled;

Fig. 11 is a schematic perspective view of a possible assembly using the third embodiment of Figs. 9 and 10.

Figs. 12 - 17 show elements of a further embodiment of cell according to the invention;

Figs. 18 and 19 show a method of assembly of the elements of Figs. 12 - 17, Fig. 19 being turned through 180° with respect to the view shown in Fig. 18;

Figs. 20 and 21 show views of a foot; and

Figs. 22 and 23 show to an enlarged scale a foot and clip.

[0033] Referring to the drawings, there is shown in Figs. 1 - 3 a drainage cell 1 (Fig. 1) for a ground water attenuation system 2 (Fig. 3) there being a plurality of such cells 1 assembled together on a plurality of base elements 3 (Fig. 2) to form a modular system 2.

[0034] It is understood herein that attenuation of water generally means the lengthening of the period during which water is held at a location where it arises e.g. at a storm area, for dispersal into the ground at that area without flowing away therefrom as for example flood water. The water is thereby held and can be disposed of in a controlled manner.

[0035] The cells 1 and base elements 3 are each moulded in one piece from plastic to form relatively rigid modules.

[0036] Each cell 1 is a rectangular parallelepiped, being defined by four boundary walls 4. Each wall 4 itself is defined by a plurality of spaced apart support elements 5 of rectangular section between which extend flat, in the embodiment, spacer elements 6, there being four as shown arranged as an upper pair 6' and a lower pair 6", the spacer elements 6 having the same width as the depth of the orthogonally arranged support elements 5 and thus providing a light yet strong wall element 4 there being between the vertically adjacent inner spacer elements 6a of each pair 6',6" a spider 7 which provides for additional strength while allowing for through passage of water. There is a lattice structure 8 for the same purpose between the spacer elements 6 of a pair.

[0037] Aligned with each support element 5 there are respective releasable interengagement means in the form of lower projections or spigots 9 and upper receiving means in the form of sockets or recesses 10.

[0038] Internally of each cell 1 there is an array of a plurality of spaced apart tube members 10 of circular section, each having a part 11, in the embodiment a lower end part, of reduced diameter and of outside diameter sufficient to be received in the open end of a the member 10 of a cell 1 on which it is placed, and for being received in a seat 12 of a base element 3.

[0039] In the embodiment, there are nine tube members 10, arranged in three parallel rows and each being connected integrally to an adjacent tube member and/or a boundary wall by webs 13 which in the embodiment are radially arranged to provide for relatively uniform distribution of an applied load.

[0040] Each base member 3 is rectangular and comprises a body defined by boundary walls 14 which rise from a web 15 having the seats 12 in the form of through holes, there being an integral array of orthogonally arranged strengthening elements 16 which interconnect with each other and with the walls 14 to define pockets 17 each of which has a through hole 12. The wall members 14 and the strengthening elements 16 are each relieved by through passageways 18 of semicircular configuration which provide lightness, strength, and passageways for water flow.

[0041] In use, a system 2 of ground water attenuation is assembled underground in a suitable pit or excavation (not shown) by laying the base elements 3 down in the desired array and then by assembly on top of a first layer of cells 1 with the tubular extensions 11 each in a respective seat 12, in the web 15.

[0042] A further layer of cells 1 is then laid on top of the first one the tubular extensions 11 being received in the open end of a respective vertically lower tube member 10, and with the projections 9 received in the holes 10. Additional layer(s) are then assembled vertically, it being understood that this system 2 is assemblable in any desired configuration.

[0043] Each cell 1, or the whole assembly 2, is covered in a cover of the embodiment, water impermeable geotexlite material (not shown), and there may be an element 3 laid on tip of the assembly 2 of the cells. The excavation is then filled in. When there is a surplus of water as in a storm, that water is led to the assembly 2 and builds up therein there being "stored", and slowly permeates therefrom into the surrounding soil. The ground water is then attenuated, and distributed at the point where it is created, and does not flow off causing erosion and perhaps flooding elsewhere. It will be understood that the modular system is strong yet light, and can support a load, for example of a lorry passing thereover or standing on it, the strength being provided by the columnar nature of the tubes, and the spacers and supports which help to spread an applied load.

[0044] Referring now to Figs. 4 - 11 of the drawings, in which like parts are referred to by like reference numerals, there is shown a drainage cell 101, 102 for a ground water attenuation system, comprising a body defined by perforated boundary walls 103, a perforated base 104, and an open top 108, there being a plurality of discrete upstanding connector members 106 rising from the base 104 towards the open top 105, and means 107 adapted for interconnection of two cells 101, 102 which in use are placed with their open tops 105 substantially parallel.

[0045] Each cell 101, 102 is in the embodiment injection moulded in one piece from plastic and forms a rectangular parallepiped. There is an inlet and/or outlet 109 for water in the form of a substantially circular seating, which has an internal spider 108 which is removable to form the seating 109, into which a water pipe can be fitted.

[0046] Each cell 101, 102, being moulded in one piece from plastic, forms a relatively rigid and strong module, which can withstand imposed loads from above. The boundary walls 103 have a structure similar to that disclosed in Figs. 1 to 3.

[0047] Referring to Figs. 4 and 5, the discrete upstanding connector members 106 comprise columns which in the left hand cell are female and in the right hand cell (as viewed in Fig. 1) are male.

[0048] Thus the cells 101 are different being unlike or dissimilar in that one is a male cell and the other female, the interaction means being the free ends of the male and female columns 106 which interengage directly when one cell 101 is placed on the other with their open tops 105 facing, as shown in Fig. 5, there being no need to rotate one cell horizontally with respect to the other through 180°. The cells 101 can simply be placed directly one on top of the other, it being understood that there are an identical number of columns 106 which are located in the same place with respect to the base 104 so that columns 106 are vertically aligned when one cell 101 is assembled with the other.

[0049] Turning now to the further embodiment of Figs. 6 to 8, each cell 102 is identical in that the connector members 106 are columns having male connections defined by reduced diameter free ends. The columns 106 both those inboard of the walls 103 of the cells 102 and those located at the walls are shorter than the height of the walls 103, in other words they do not extend to or reach the open top 105. Thus two cells cannot normally be interconnected. Interconnection is achieved by the use of interconnection means 107 in the form of a separate grid 107' which has female connectors 110 in the form of female tubes which are each positioned at a location corresponding with that of a respective column 106 of a cell 102. The grid 107' has an area substantially equal to that of the open top 105.

[0050] In use to interconnect the cells 102 to make an assembly, the grid 107' is offered up to and placed on the open top 105 of one cell 102 so that the female tubes 110 receive a male column 106 of the cell 102.

[0051] The second, identical cell 102 is then placed, open top 105 downwards, on the grid 107' so that its male columns 6 enter the upstanding female tubes 110 of the grid 107'. The cells 102 are then firmly assembled to provide a drain box with their open tops facing.

[0052] The grid 107' comprises webbing 111 to support the female tubes above and below it, the grid 111 being formed integrally by injection moulding. It will be understood that the tubes 110 could be used individually. In either case, the two cells 102 cannot interact as the columns never interact directly.

[0053] The perforated side walls are only 2.5mm thick. The cells and corresponding connector element would be factory assembled. The cell being designed such that the two cells cannot be connected without the third connecting element or grid 107'. When in place the connecting element 107' prevents all columns in the cell from interacting or touching. If the connecting element were left out or removed from the box the cells could not be connected as they are common (male to male). In other words a closed box could not be made. For this reason the connecting element 107' must be included, and when included, all columns cannot interact.

[0054] Referring now to the third embodiment of Figs. 9 to 11, there is a cell 102 which has upstanding connector members 106 in the form of male columns. The interconnection means is in the form of a cover 107" for the open top 105 which has female parts 107"' for receiving a respective male column 106 to form a closed unit 130. Such a unit can be installed by turning upside down (Fig. 11), and a further cell 102 can then be connected to it by interengagement of separate connectors such as pegs (not shown), which are received with a push or other interlocking fit in an open base of the columns 106. Two cells 102 which have their open tops parallel, while not facing as in the other two embodiments, cannot be connected open top to open top as the male columns interfere with one another and cannot be interconnected. The cells can only be connected open top to closed bottom, Fig. 11.

[0055] In a further embodiment, not shown, cells 101, 102 may be variable in height. In such a construction the grid 107' of the second embodiment would be replaced by a lid on the half box or cell to make a closed unit of effectively half height. In this way the box produced would be made from two separate and dissimilar components.

[0056] Referring now to Figs. 12 - 17, there is shown a cell 201 and a cell 202, of similar construction to the cells of say Fig. 1 or Fig. 4. In the embodiment of Figs. 12-17, the columns 203 are predominantly female and extend towards the open face 204 of the cell 201, 202 to lie substantially planar with respect to the plane thereof.

[0057] Two cells 201, 202 are then assembled in open face-to-face contact using a grid 205 which has projecting spigots or columns 206 each spigot or column being a male member which projects in opposite directions from the plane of the grid 206 to enter the columns 203 and thus form an assembled attenuation cell assembly 207 stacked in use vertically, as shown in Fig. 15.

[0058] Fig. 16, which shows an exploded perspective view of the assembled cell also shows that for each cell 201, 202, which is oblong in plan, there are two substantially square grids 206.

[0059] Each grid 206 has at respective edges a plurality of selected spigots 208 which are essentially half spigots which define an internal clipping system 209 as shown in Figs. 18 and 19. This clipping system 209 comprises inherently resilient clip means 210 which spring engages being a web of a column 203 to secure the two cell parts 201, 202 together via the grid 206 when the grid 206 is snap engaged with one cell 201, and then with the other 202 when that other cell is offered up to the protruding spigots of the grid and lowered thereinto, to form the assembled structure of Fig. 15.

[0060] To achieve this clipping, a plurality, in the embodiment 4, of the columns 203 have discs 211 which are internally of the columns and spaced from the internal surface of the columns to provide a gap of sufficient width to receive the means 210. There is thus a "click" connection and a positive locking action of the grid 206 and the cells 201, 202.

[0061] Comer spigots also have a clip connector 212 at a central position in use, of the grid 206.

[0062] A cell 201, 202 can be supported above a substrate by a plurality of spaced apart discrete feet 300, shown in Fig. 22, which have a rounded outer surface 301 to assist in movement over the ground, and which have resilient projections or legs 302 with releasable interengagement means in the form of integral hooks 304, which can be engaged in the wall perforation of a cell 201, 202 to hook behind a wall element thereof, and which rests on outer face ribbing of a cell via a peripheral shoulder 305.

[0063] There are preferably eight feet 300 per cell, 201, 204, which when installed effectively convert a cell 201, 202 into a pallet. Thus by using the eight feet 300 spaced apart round a cell which is to be the base of a stack of assembled cells, e.g. in Figs. 12 to 19, the lower cell is spaced from the ground a sufficient distance for tines of a fork-lift truck or the like to be inserted between them so that the whole assembled stack of assembled cells can readily be transported. When at a point of use, the feet 300 can be disengaged and removed simply by springing the hook member 304 out from behind a wall of the cell.

[0064] The clip member 400 of Fig. 23 is a one-piece member which is of generally U-configuration, and can be used to secure cells 201, 202 together in side-by-side relation, thereby providing for lateral extension of an array of cells. The clips 400 simply are a push fit of their legs 401 over the top of the two adjacent lateral walls of two laterally adjacent cells. The legs 401 are of an inherently resilient nature, being suitably made from plastic in one piece so that the legs 401 are pushed apart on pushing down over the adjacent walls, which are touching, so that when the web 402 is in place on the upper surface of the walls, the natural resilience of the legs 401 tends to want them to return to their initial position, so gripping the walls of the cells 201, 202 and thereby holding two laterally adjacent cells together laterally. The clips 400 can readily be removed just by moving in the opposite direction to the assembly direction.

[0065] In all embodiments, an assembly of cells is installed in a pit or excavation and connected as part of a system for dealing with rainwater collection and/or distribution by connection with pipes inserted in the seatings 109. The cells 101, 102 may be covered with a geotextile material, which may be water permeable or water impermeable.

Claims

1. A drainage cell for a ground water handling system, comprising a body defined by perforated boundary walls, a perforated base, and an open top, there being a plurality of discrete upstanding connector members rising from the base towards the open top, and means adapted for interconnection of two cells which in use are placed with their open tops substantially parallel.

2. A drainage cell according to Claim 1, characterised by the walls each having respective releasable interengagement means, the arrangement being such that one cell can be releasably mountable on another similar cell with respective tube members and releasable interengagement means in cooperation to provide a modular construction.

3. A cell according to Claim 2, characterised by the connector members comprising upstanding columns, there being in a cell identical columns which are either male columns or female columns which form said interconnection means, whereby when a cell having male interconnection means is assembled open top to open top with a cell having female interconnection means, the two cells are interconnected.

4. A cell according to any preceding claim, characterised by the respective releasable interengagement means comprising projecting means at one edge of one wall and respective cooperable receiving means at an opposite edge of the wall.

5. A cell according to Claim 4, characterised by the receiving means comprising sockets.

6. A cell according to Clam 4 or Claim 5, characterised by the tubes each being circular in cross-section, the part of reduced dimension comprising a tubular extension of less diameter than that of the tube.

7. A cell according to Claim 6, characterised by the tubes being connected with each other externally and/or to the walls by cells.

8. A cell according to Claim 7, characterised by the webs being radial webs.

9. A cell according to any preceding claim, characterised by the walls being defined by spaced apart substantially parallel spacer elements extending between substantially orthogonally arranged support elements.

10. A cell according to Claim 9, characterised by the spacer elements being substantially flat.

11. A cell according to Claim 9 or claim 10, characterised by the support elements being substantially square in cross-section.

12. A cell according to Claim 10 or Claim 11, characterised by there being four spacer elements extending between two adjacent support elements.

13. A cell according to Claim 12, characterised by the four spacer elements comprising in use an upper pair and a lower pair of spacer elements.

14. A cell according to Claim 1, characterised by the interconnection means comprising a separate device adapted for interposition between two cells having their open tops facing.

15. A cell according to Claim 14, characterised by the connector members comprising columns each defining a male or female connector.

16. A cell according to Claim 14 or Claim 15, characterised by the separate device comprising a grid defining a plurality of discrete female or male connection means adapted for interconnection with a respective male or female connector member of a cell.

17. A cell according to either of Claims 15 or 16, characterised by the connector members being male and terminating below the height of the boundary walls.

18. A cell according to Claim 16, characterised by the connection means of the device being female and having a height adapted for interconnection with the male connector members whereby two cells may be interconnected with their open tops facing.

19. A cell according to Claim 18, characterised by the interconnection means comprising a grid adapted for interengagement with the connector members of the cell whereby to close the open top and a plurality of further connector elements for connecting a cell and grid assembly with another cell having its open top facing the originally open top of the cell of the cell and grid assembly.

20. A cell according to Claim 19, characterised by the spigots protruding in opposite directions from the grid to provide for connection between two superposed cells.

21. A cell according to Claim 20, characterised by some at least of the spigots having means to engage with a locking element of a female member of a cell.

22. A cell according to Claim 21, characterised by said means comprising resilient hook means and disc means.

23. A cell according to Claim 22, characterised by the discrete upstanding connector elements of each cell defining male connector members.

24. A cell according to any of Claims 14 to 22, characterised by means defining an inlet and/or outlet for water in at least one boundary wall.

25. A cell according to Claim 24, charactrised by the inlet and/or outlet comprising a substantially circular seating for receiving a pipe for water.

26. A cell according to Claim 25, characterised by the seating having an integral spider which is removable to define an entry for the pipe.

27. A cell according to any preceding claim, integrally moulded in one piece from plastic materials.

28. A cell according to Claim 27, characterised by being made by injection moulding.

29. A set of parts for assembly to form a ground water attenuation system, comprising a plurality of drainage cells according to any preceding claim, and a plurality of separate base members, the base members and cells being assemblable to provide the system.

30. A set according to Claim 29, characterised by the base members each comprising a plurality of seats for receiving a respective reduced dimension part of a tube.

31. A set according to Claim 30, characterised by the seats each comprising a through hole in a web of the base member.

32. A set according to Claim 31, characterised by the base members each being defined by a boundary wall upstanding from the wall.

33. A set according to Claim 32, the wall have a plurality of through passageways adjacent the web.

34. A set according to any of Claims 29 to 33, characterised by including a geotexlite cover for the set, or for an individual cell of the set.

35. A set according to Claim 34, characterised by the cover being water impermeable.

36. A set according to any of Claims 29 to 35, characterised by a plurality of foot members adapted for releasable engagement with one cell of the set.

37. A set according to Claim 36, characterised by eight foot members having resilient releasable interconnection with said cell.

38. A set according to any of Claims 29 to 37, characterised by a device for securing two cells together laterally.

39. A base member for supporting a cell of a ground water attenuation system comprising a body defined by a web and boundary walls projecting therefrom, the web having a plurality of spaced apart through bores, for receiving a corresponding part of a cell in use.

40. A groundwater attenuation system, comprising a cell or cell assembly according to any preceding claim.

41. A system according to Claim 40, characterised by the cell or cell assembly being covered in a geotextile material.

42. A system according to Claim 41, characterised by the material being water impermeable.

Drawing