Abstract
A ground stabilisation system, a cell assembly and a kit of parts for such a system, and methods of making and installing such cell assemblies are disclosed. A cell assembly (1701) comprises a rock containment cell having a bottom, first and second sides, first and second ends and a top each formed from chain-link wire mesh, wherein a first continuous sheet of mesh (1710) wraps around and defines the upper, lower and end faces of the cell assembly and is joined end to end by an overlapping join. The first side face is defined by a continuous length of chain-link wire mesh that at least partially wraps around another adjacent face of the cell assembly, and the second side face of the cell assembly is defined by a continuous length of chain-link wire mesh that at least partially wraps around another adjacent face of the cell assembly. The mesh defining the first and second side faces may be a single continuous sheet (1720).
Claims
1.-33. (canceled)
34. A cell assembly for a ground protection system, the cell assembly having opposed upper and lower faces, opposed first and second end faces and opposed first and second side faces, wherein the cell assembly comprises at least one cell for containment of rock pieces; wherein a first continuous length of chain-link wire mesh wraps around and defines the opposed upper and lower faces and the opposed first and second end faces of the cell assembly, the first continuous length of wire mesh comprising a single continuous sheet of chain-link wire mesh having a first end and a second end overlapped and fastened together to form an overlapping join positioned on the upper, first end and/or second end face of the cell assembly, wherein the single continuous sheet wraps around the cell assembly and spans each of the upper, lower and first and second end faces of the cell assembly, wherein the first side face of the cell assembly is defined by a second continuous length of chain-link wire mesh that at least partially wraps around a face of the cell assembly adjacent the first side face, the second continuous length comprising a single continuous sheet of chain-link wire mesh that spans the first side face and extends across at least a portion of said adjacent face; and wherein: the second side face of the cell assembly is also defined by the second continuous length of chain-link wire mesh, wherein the single continuous sheet of the second continuous length spans the second side face and spans said adjacent face of the cell assembly; or the second side face of the cell assembly is defined by a third continuous length of chain-link wire mesh that at least partially wraps around a face of the cell assembly adjacent the second side face, the third continuous length comprising a single continuous sheet of chain-link wire mesh that spans the second side face and extends across at least a portion of said adjacent face.
35. The cell assembly of claim 34, wherein the first continuous length of chain-link wire mesh consists of said single continuous sheet of chain-link wire mesh.
36. The cell assembly of claim 34, wherein the second continuous length of chain-link wire mesh defines both the first and second side faces and extends across the lower face of the cell assembly, thereby overlapping the first continuous length of wire mesh on the lower face of the cell assembly, wherein the single continuous sheet of chain-link wire mesh spans the first and second sides faces and the lower face of the cell assembly and extends across at least a portion of the upper face of the cell assembly.
37. The cell assembly according to claim 36, wherein the single continuous sheet of the second continuous length has a first end and a second end, said first and second ends being overlapped and fastened together to form another overlapping join positioned on the upper, first side and/or second side face of the cell assembly, preferably the upper face.
38. The cell assembly of claim 36, wherein the second side face is defined by the third continuous length of chain-link wire mesh, wherein the single continuous sheet of the second continuous length and the single continuous sheet of the third continuous length each extend across at least a portion of the upper face of the cell assembly.
39. The cell assembly of claim 36, wherein the second continuous length consists of said single continuous sheet of chain-link wire mesh, and wherein the third continuous length, if present, consists of said single continuous sheet of chain-link wire mesh.
40. The cell assembly according to claim 34, wherein the cell assembly comprises a plurality of cells, wherein one or more chain-link wire mesh baffles separate the cells to subdivide the cell assembly.
41. The cell assembly according to claim 34, comprising a strengthening grid positioned inside one or more cells, the strengthening grid being a welded wire mesh formed from stainless steel rods each having a diameter of at least 8 mm, wherein the strengthening grid extends across at least 75% of a first internal width and across at least at least 75% of a second internal width of the cell, wherein the first internal width is the distance between opposed ends, and the second internal width is the distance between opposed sides, of the cell.
42. The cell assembly according to claim 34, wherein the wire mesh is formed from high tensile stainless steel wire having a diameter of at least 2 mm and a tensile strength of at least 1,000 N/mm.sup.2; optionally wherein sheets of wire mesh are fastened together with tie wires and/or a plurality of clips, wherein the tie wires and/or the plurality of clips are formed from high tensile stainless steel wire having a diameter of at least 2 mm and a tensile strength of at least 1,000 N/mm.sup.2.
43. The cell assembly according to claim 34, wherein the sheets of chain-link wire mesh forming the continuous lengths of chain-link wire mesh are each formed from interlaced wires extending from one side edge to an opposed side edge in a direction parallel to the opposed end edges, and wherein wire ends are knotted into loops that interlock with a corresponding loop on the end of an adjacent wire.
44. The cell assembly according to claim 34, wherein the cell assembly comprises a plurality of lift assemblies, each lift assembly comprising a lift plate positioned below the lower face of the cell assembly, and a lift cable secured to the lift plate and extending upwards through the cell assembly and outwards from the upper face, wherein each lift cable is configured for attachment to a lifting device, such as a lifting frame.
45. The cell assembly according to claim 34, wherein the cell assembly comprises: a plurality of vertical brace assemblies tying the wire mesh extending across the lower face of the cell assembly to the wire mesh extending across the upper face of the cell assembly, wherein each vertical brace assembly comprises a lower brace plate disposed below the wire mesh of the lower face of the cell assembly, an upper brace plate disposed above the wire mesh of the upper face, and a tensioning member joining the lower brace plate to the upper brace plate, and/or at least one horizontal brace assembly tying the wire mesh extending across a side or end face of the cell assembly to the wire mesh extending across the opposing side or end face of the cell assembly, wherein each horizontal brace assembly comprises a first brace plate disposed outside the wire mesh of the side or end the cell assembly, a second brace plate disposed outside the wire mesh of the opposed side or end, and a tensioning member joining the first brace plate to the second brace plate.
46. A ground protection system comprising a plurality of cell assemblies according to claim 34, wherein the cell assemblies are secured together; optionally wherein each cell assembly has a brace assembly fastened to a brace assembly on another cell assembly, for example wherein the cell assemblies are cell assemblies wherein the cell assembly comprises: a plurality of vertical brace assemblies tying the wire mesh extending across the lower face of the cell assembly to the wire mesh extending across the upper face of the cell assembly, wherein each vertical brace assembly comprises a lower brace plate disposed below the wire mesh of the lower face of the cell assembly, an upper brace plate disposed above the wire mesh of the upper face, and a tensioning member joining the lower brace plate to the upper brace plate, and/or at least one horizontal brace assembly tying the wire mesh extending across a side or end face of the cell assembly to the wire mesh extending across the opposing side or end face of the cell assembly, wherein each horizontal brace assembly comprises a first brace plate disposed outside the wire mesh of the side or end the cell assembly, a second brace plate disposed outside the wire mesh of the opposed side or end, and a tensioning member joining the first brace plate to the second brace plate; and wherein at least one tensioning member of a vertical or horizontal bracing assembly of each cell assembly is connected to a corresponding tensioning member of a vertical or horizontal bracing assembly of an adjacent cell assembly.
47. A kit of parts comprising parts for forming the cell assembly of claim 34, the kit of parts comprising: at least one chain-link wire mesh sheet for forming the first continuous length of chain-link wire mesh for defining the lower, first and second end and upper faces of the cell assembly, at least one additional chain-link wire mesh sheet for forming the second continuous length of chain-link wire mesh, and the third continuous length if present, for defining the first and second side faces of the cell assembly, each additional continuous chain-link wire mesh sheet being arranged for defining a side face and at least partially wrapping around another adjacent face of the cell assembly, and, fastenings for forming overlapping joins between sheets, and a forming frame for supporting the sides and ends of the cell assembly during construction and filing with fill material, the forming frame being an open-topped frame sized to extend around the first and second sides and the first and second ends of the cell assembly.
48. The kit of parts according to claim 47, comprising a plurality of vertical and/or horizontal brace assemblies for tying wire mesh extending across the lower face to wire mesh extending across the upper face of the cell assembly and/or wire mesh extending across the first side/end to wire mesh extending across the second side/end, wherein each brace assembly comprises a lower/first brace plate, an upper/second brace plate, and a tensioning member for joining the lower/first brace plate to the upper/second brace plate, and optionally a retainer for holding the upper/second brace plate in position on the tensioning member; optionally wherein a plurality of the brace assemblies is configured for suspending the cell assembly from a lifting device, such as a lifting frame, once the cell assembly is constructed and the cell(s) filled with fill material, for example wherein each tensioning member of said brace assemblies is configured for attachment to a lifting device.
49. The kit of parts according to claim 47, comprising a plurality of lift assemblies for suspending the cell assembly from a lifting device, such as a lifting frame, once the cell assembly is constructed and the cell(s) filled with fill material, wherein each lift assembly comprises a lift plate and a lift cable securable to the lift plate and connectable to said lifting device.
50. The kit of parts according to claim 47, wherein the cell assembly comprises a plurality of cells, wherein the kit comprises at least one chain-link wire mesh panel for forming a baffle for subdividing the cell assembly into the plurality of cells.
51. A method of constructing a cell assembly according to claim 34, the method comprising: fastening the first continuous length of chain-link wire mesh for defining the lower, first and second end and upper faces of the cell assembly to the second continuous length of chain-link wire mesh, and the third continuous length if present, for defining the first and second side faces of the cell assembly, wherein the at least one cell has an open top, inserting fill material into the at least one cell, and securing the first continuous length of chain-link wire mesh across the upper face of the cell assembly by fastening together the ends of each continuous sheet of chain-link wire mesh forming the first continuous length, and fastening the first continuous length of chain-link wire mesh to the second continuous length of chain-link wire mesh, and the third continuous length if present, for defining the first and second side faces, thereby closing the at least one cell so that the first continuous length of chain-link wire mesh defining the first and second end and upper faces of the cell assembly overlaps and/or is overlapped by the second continuous length of chain-link wire mesh, and the third continuous length if present, defining the first and second sides of the cell assembly; optionally wherein the method comprises using a forming frame to control the shape of the cell assembly during the step of filling the at least one cell, optionally wherein fill material is compacted before the step of closing the at least one cell.
52. The method according to claim 51, comprising installing at least part of one or more brace assemblies in the cell assembly before the step of inserting fill material into the at least one cell, and completing the brace assemblies after the step of closing the cells to tie wire mesh extending across the lower face of the cell assembly to wire mesh extending across the upper face; and/or comprising installing a plurality of lift assemblies in the cell assembly before the step of inserting fill material into the at least one cell.
53. A method of constructing a ground protection system, the method comprising lifting a plurality of cell assemblies according to claim 34 into an installation position by suspending each cell assembly from a lifting device, such as a frame, and securing the cell assemblies together, such as by connecting at least one brace assembly of each cell assembly to a brace assembly of another cell assembly, for example by connecting together tensioning members of said brace assemblies.
Description
DESCRIPTION OF THE DRAWINGS
[0054] Embodiments of the present invention will now be described by way of example only with reference to the accompanying schematic drawings of which:
[0055] FIGS. 1a and 1b show prior art gabion designs;
[0056] FIGS. 2a-c show various views of a cell assembly during construction;
[0057] FIGS. 3a-e show various views of a cell assembly, during and after construction;
[0058] FIGS. 4a-e show various views of another cell assembly, during and after construction;
[0059] FIG. 5a shows a top plan view of a wire mesh for use in the assembly of the invention;
[0060] FIG. 5b shows a side view of the wire mesh of FIG. 5a;
[0061] FIG. 6a shows a helicoil fastening for fastening together panels of wire mesh;
[0062] FIG. 6b shows a c-clip for fastening together panels of wire mesh;
[0063] FIG. 6c shows a spring clip suitable for fastening together panels of wire mesh;
[0064] FIG. 7 shows a side cross-section view of a cell assembly fitted with a permeable barrier;
[0065] FIG. 8 shows a perspective view of a cell assembly fitted with a fines barrier bag filled with sand, soil, rocks or a mixture thereof;
[0066] FIG. 9 shows a perspective view of a cell assembly having vertical and horizontal bracing;
[0067] FIG. 10 shows a side cross-section view of a cell assembly positioned on the ground;
[0068] FIG. 11 shows a side cross-sectional view of another cell assembly identical to that of FIG. 10, except that it also comprises a horizontal brace assembly;
[0069] FIG. 12 shows a side cross-section view of three of the cell assemblies of FIG. 10 positioned adjacent each other and joined by their brace assemblies;
[0070] FIG. 13 shows a side cross-section view of two of the cell assemblies of FIG. 11 positioned adjacent each other and joined by their brace assemblies.
[0071] FIG. 14 shows a top perspective view of two of the cell assemblies of FIG. 10 positioned adjacent each other and joined by their brace assemblies;
[0072] FIG. 15 shows a top perspective view of two of the cell assemblies of FIG. 11 positioned adjacent each other and joined by their brace assemblies
[0073] FIGS. 16a and 16b show a fines barrier bag for a cell assembly in open and closed configurations;
[0074] FIGS. 17a-g show various perspective views of a cell assembly being constructed and lifted.
DETAILED DESCRIPTION
[0075] FIGS. 2a-c show exploded and partially constructed views of a cell assembly 201 according to the invention. Cell assembly 201 is a single cell assembly comprising a one cell. The cell assembly 201 has a lower face 202, two opposed side faces 203b and 203d, and two opposed end faces 203a and 203c. The cell assembly 201 is formed from two overlapping continuous lengths of wire mesh 210, 220 shown separately in FIGS. 2a and 2b, respectively. A first length of mesh is formed from two single continuous sheets 210a, 210b joined together side to side by an overlapping join 230a, and a second length of mesh is formed from two single continuous sheets 220a, 220b joined together side to side by an overlapping join 230b. Once the two sheets 210, 220 are put together to form the cell assembly 201, sheet 210 wraps around the lower face 202 and the two opposed side faces 203b, 203d, and sheet 220 wraps around the lower face 202 and the two end faces 203a, 203c. Sheets 210a, 210b of length 210 each wrap around and span lower face 202 and the two opposed side faces 203b, 203d, and each sheet is joined to itself end to end by an overlapping join. Similarly, sheets 220a, 220b of length 220 each wrap around and span lower face 202 and the two opposed end faces 203a, 203c, and each sheet is joined to itself end to end by an overlapping join. The cell assembly 201 is shown in FIG. 2c in a partially constructed state, with the top of the cell open. To close the cell, the ends 214a, 214b of sheet 210, and the ends 224a, 224b of sheet 220 are folded in over the upper face of the cell, with the opposing ends of sheets 210 and 220 overlapping in the middle. Once closed, cell assembly 201 has at least a double layer of mesh entirely across the lower face 202, and across the upper face. Fastenings, e.g. helicoil fastenings, may be used between sides of the sheets at edges of the cell. In FIGS. 2a-c, the wire mesh forming the cell is a diamond pattern, chain link, wire mesh, shown only on end 203a and side 203d for clarity. Each sheet 210a, 210b, 220a, 220b is made up of a plurality of interlaced, zig-zag shaped wires that extend from one side of the sheet to the other in a general direction parallel to each other and parallel to the ends of the sheets.
[0076] FIGS. 3a-c show exploded and partially constructed perspective views of a cell assembly 301 according to the invention. FIG. 3d shows a top plan view of the cell assembly 301, and FIG. 3e shows a perspective view of the cell assembly 301 when complete (except that the rock filling is not shown for clarity). Cell assembly 301 is a single cell assembly comprising a one cell. The cell assembly 301 has a lower face 302, two opposed side faces 303b and 303d, and two opposed end faces 303a and 303c. The cell assembly 301 is formed from two overlapping continuous sheets of wire mesh 310, 320, shown separately in FIGS. 3a and 3b, respectively. Once the two sheets 310, 320 are put together to form the cell assembly 301, sheet 310 wraps around the lower face 302 and the two opposed side faces 303b, 303d, and sheet 320 wraps around the lower face 302 and the two end faces 303a, 303c. The cell assembly 301 is shown in FIG. 3c in a partially constructed state, with the top of the cell open. To close the cell, the ends 314a, 314b of sheet 310, and the ends 324a, 324b of sheet 320 are folded in over the upper face of the cell, with the opposing ends of sheets 310 and 320 overlapping in the middle. It will be appreciated that sheet 310 may be located inside sheet 320, outside sheet 320, or inside sheet 320 on the lower face and outside sheet 320 on the upper face (and vice versa). The structure of cell 301 has a double layer of mesh across the lower face 302, and at least a double layer across the upper face (with four layers of mesh across at least a portion of the upper surface). FIG. 3d shows the four-way overlap created when the top of the cell is closed to form overlapping join 330, where the overlapping sheets are joined by a suitable fastening device, such as a helicoil fastener. Fastenings, e.g. helicoil fastenings, may be used between sides of the sheets at edges of the cell. The brace assemblies 340 are positioned to pass through the four way overlapping join 330, strengthening the overlapping join. FIGS. 3a-e show cell 301 with both continuous sheets overlapped on the upper face of the cell. It will be appreciated that the two sheets need not overlap on the same face. For example, overlaps between sheets could be formed on the side or end faces instead. In FIGS. 3a-e, the wire mesh forming the cell is a diamond pattern, chain link, wire mesh, shown only on end 303a and side 303d for clarity. Each sheet is made up of a plurality of interlaced, zig-zag shaped wires that extend from one side of the sheet to the other in a general direction parallel to each other and parallel to the ends of the sheets. The diamond shaped openings of the mesh have lengths greater than their widths, forming an elongate diamond. In FIGS. 3a-e, the meshes of both sheets 310, 320 are oriented with the length axis of the diamonds parallel the bottom of the cell. Other mesh shapes could be used, e.g. the diamonds could have their length axis perpendicular the bottom of the cell, as would be the case using the mesh of FIG. 5a. FIGS. 3a-e show cell 301 with the sheets 310, 320 forming a double layer on the lower and upper faces of the cell. Alternative constructions include having mesh 310 extend only across the lower and side faces (and not the upper face), and/or having mesh 310 turned to wrap the side and end faces of the cell rather than the lower, side and upper faces. It will be appreciated that the opposed ends of, e.g., the sheet 310 need not overlap each other, for example provided that they overlap with the other sheet 320 (and vice versa). Four brace assemblies 340 are shown in FIGS. 3d-e to give an indication of their positions once the cell assembly is constructed.
[0077] FIGS. 4a-e show various views of another cell assembly 401 according to the invention. Cell assembly 401 is similar to cell assembly 301 of FIGS. 3a-e, except that it is formed from three overlapping continuous sheets of wire mesh 410a, 410b, and 420, shown separately in FIGS. 4a and 4b, respectively. Features the same as those in FIGS. 3a-e are given corresponding reference numerals, prefixed 4 instead of 3. Once the three sheets 410a, 410b, 420 are put together to form the cell assembly 401, sheet 410a defines the first side face 403b, sheet 410b defines the second side face 403d, and sheet 420 wraps around the lower face 402 and the two end faces 403a, 403c. The cell assembly 401 is shown in FIG. 4c in a partially constructed state, with the top of the cell open. To close the cell, the ends 414a, 414b of sheets 410a, 410b, and the ends 424a, 424b of sheet 420 are folded in over the upper face of the cell, with the ends 414a, 414b of sheets 410a, 410b and the opposing ends of sheet 420 overlapping in the middle. It will be appreciated that sheets 410a, 410b may be located inside or outside sheet 420 on the upper face. The structure of cell 401 has a single layer of mesh across the lower face 402, and at least a double layer across the upper face (with four layers of mesh across at least a portion of the upper surface). FIG. 4d shows the four-way overlap created when the top of the cell is closed to form overlapping join 430, where the overlapping sheets are joined by a suitable fastening device, such as a helicoil fastener. Fastenings, e.g. helicoil fastenings, may be used between sides of the sheets at edges of the cell. The brace assemblies 440 are positioned to pass through the four way overlapping join 430, strengthening the overlapping join. FIGS. 4a-e show cell 401 with all three sheets overlapped on the upper face of the cell. The wire mesh forming the cell is a diamond pattern, chain link, wire mesh, shown only on end 403a and side 403d for clarity.
[0078] The cell assemblies of FIGS. 3a-e and 4a-e are each suitable for defining the bottom and sides of a cell having a width of 3.25 m, a length of 3.25 m and a height of 0.75 m. The wire mesh forming the panels is Geobrugg? TECCO? high-tensile steel wire mesh G65/3 stainless, having a wire diameter of 3.0 mm, and a wire tensile strength of at least 1,650 N/mm.sup.2, formed from AISI 318 stainless steel. The mesh tensile strength is at least 140 kN/m. The diamond openings are 143 mm long, and 83 mm wide. Other wire meshes could be used, including Al/Zn coated steel wire mesh, such as other Geobrugg? TECCO? products.
[0079] FIG. 5a shows a top plan view of a wire mesh suitable for use in the cell assembly of the invention. Shown in FIG. 5a is Geobrugg? TECCO? mesh. Optionally, the mesh is G65/3 STAINLESS TECCO? mesh. The mesh is a chain-link woven mesh having a diamond pattern, with each diamond opening having a length L greater than a width W. The mesh portion shown in FIG. 5a is made up of six zig-zag interlaced wires 501-506. The cut ends of each wire 501a, 502b are knotted and interlinked with the knotted cut ends of the adjacent wire 502a, 502b. FIG. 5b shows a side view of the wire mesh of FIG. 5a.
[0080] FIG. 6a shows a helicoil fastening 601 suitable for fastening together panels of wire mesh. In use, the helicoil fastening 601 is wound around the wires of two adjacent mesh panels to link the panels together. FIG. 6b shows a c-clip 602 suitable for fastening together panels of wire mesh. The c-clip is shown in two configurationsopen (before being used to fasten panels together, when the clip has a c shape), and closed (after being secured around a pair of adjacent wires to fasten wires together, when the clip overlaps itself to form an o shape). In FIG. 6b, the clip in its close configuration is shown in plan view and side view to show the overlapping clip ends. FIG. 6c shows a spring clip 603 suitable for fastening together panels of wire mesh. The clip shown is a T3 clip available from Geobrugg?.
[0081] FIG. 7 shows a side cross-section view of a cell assembly 701 fitted with a water permeable fines barrier 720. The fines barrier is in the form of a bag that lines the bottom, sides and top of the cell 701. The fines barrier bag 720 is biodegradable, and formed from a sheep wool material, although other biodegradable materials could be used. It will be appreciated that in some installation locations, a non-biodegradable fines barrier bag may be appropriate. The fines barrier bag 720 is filled with sand, pushing the bag out against the panels defining the bottom and sides of the cell. FIG. 7 is a schematic view of a single cell 701, shown in position in an erosion protection system for clarity. Also shown in FIG. 7 is a scour prevention layer 703 comprising a (biodegradable or non-biodegradable) geotextile material. The scour prevention layer 703 is optional, but may assist in avoiding undermining of the cells in the event that water tracks along the bottom of the cells below the fines barrier bags 720. The scour prevention layer 703 is sandwiched between the cell 701 and the ground 704 requiring erosion prevention. A first continuous sheet of wire mesh wraps around the bottom, ends and top of the cell, and a second continuous sheet of wire mesh wraps around the bottom, sides and top of the cell. The cell 701 comprises a plurality of brace assemblies 707 that help keep the top and bottom of the cell in alignment with each other. FIG. 7 shows the cell 701 with a number of established live plants 708. If the cell is installed on land, examples if suitable plants include marram grass plants (which grow significant root systems that extend throughout the cell, into neighbouring cells (not shown in FIG. 7), and/or into the ground 704). Other plants may be used, e.g. if the cell is installed underwater. Plant root systems can stabilise the sand filling the cell, holding it in place as the fines barrier bag 720 naturally degrades. Marram grass plants may, for example, stimulate formation of a sand dune system over the base provided by the erosion prevention system.
[0082] FIG. 8 shows a perspective view of a cell assembly 801 similar to cell assemblies 301 and 401 of FIGS. 3 and 4, except that the cell assembly 801 is fitted with a fines barrier bag 820 filled with sand, soil, rocks or a mixture thereof. The features of the cell assembly 801 equivalent to those of cell assembly 301 are labelled with the same reference numerals as used in FIG. 3, prefixed 8 instead of 3. FIG. 8 shows the position of sixteen plants 808 (only the tops of the plants are shown in FIG. 8). The plants protrude through slits in the top of the fines barrier bag 820 (not shown in FIG. 8).
[0083] FIG. 9 shows a perspective view of another cell assembly 901 similar to cell assemblies 301 and 401 of FIGS. 3 and 4, except that in addition to the vertical brace assemblies (labelled 940 in FIG. 9), the cell assembly 901 includes a horizontal brace assembly 941 tying together opposed side faces 903b and 903d. The features of the cell assembly 901 equivalent to those of cell assembly 301 are labelled with the same reference numerals as used in FIG. 3, prefixed 9 instead of 3.
[0084] FIG. 10 shows a side cross-section view of a cell assembly 1001 similar to cell assemblies 301 and 401 of FIGS. 3 and 4, positioned on the ground 1020. The features of the cell assembly 1001 equivalent to those of cell assembly 301 are labelled with the same reference numerals as used in FIG. 3, prefixed 10 instead of 3. The vertical brace assemblies 1040 each comprise a length of cable 1040c fastened at one end to a lower brace plate 1040a positioned below the mesh forming the bottom 1002 of the cell assembly 1001, and which passes through an upper brace plate 1004b positioned above the mesh forming the top 1004 of the cell assembly 1001. When the cell assembly is constructed, the cables 1040c are pulled tight and the upper brace plates 1040b are pushed down against the top 1004 of the cell assembly 1001 and held in pace with a one-way clip (not shown in FIG. 10). In FIG. 10, the free ends of the cables 1040c are shown terminating in connectors 1040d configured for connection to corresponding connectors on the ends of such cables in neighbouring cell assemblies. Alternatively, a single connector may be added to the free ends later, for example allowing an overlapping join between cable ends.
[0085] FIG. 11 shows a side cross-sectional view of another cell assembly 1101 identical to the cell assembly 1001 of FIG. 10 on the ground 1120, except that the cell assembly also comprises a horizontal brace assembly 1141. The horizontal brace assembly 1141 comprises a length of cable 1141c that passes through a first side bracing plate 1141a positioned outside the mesh forming the first side 1103b of the cell assembly 1101, and through a second side bracing plate 1141b positioned outside the mesh forming the second side 1103d of the cell assembly 1101. When the cell is constructed, the cables 1141c is pulled tight and the first and second side brace plates 1141a, 1141b are each pushed against the first and second sides 1103b, 1103d of the cell assembly 1001 and held in pace with one-way clips (not shown in FIG. 11). In FIG. 11, the free ends of the cables 1141c are shown terminating in optional connectors 1141d configured for connection to corresponding connectors on the ends of such cables in neighbouring cell assemblies, and/or for connection to an anchoring device (e.g. a ground anchor). In FIG. 11, the labels of vertical brace assemblies 1140 are omitted for clarity.
[0086] FIG. 12 shows a side cross-section view of three of the cell assemblies 1001 of FIG. 10 (labelled 1001a-c in FIG. 12) positioned adjacent each other on the ground 1220. The cell assemblies 1001 are joined together by connecting the free ends of the cables 1040c of the brace assemblies 1040 using cable-end connectors 1040d. Any suitable cable connecting device could be used. The free ends of the cables of brace assemblies of the two outer cell assemblies 1001a and 1001c are shown ready for connection to further cell assemblies.
[0087] FIG. 13 shows a side cross-section view of two of the cell assemblies 1101 of FIG. 11 (labelled 1101a-b in FIG. 13) positioned adjacent each other on the ground 1320. The cell assemblies 1101 are joined together by connecting the free ends of the cables 1140c of the vertical brace assemblies 1140 using cable-end connectors 1140d. The cell assemblies 1101 are also joined together by connecting the free ends of the cables 1141c of the horizontal brace assemblies 1141 using cable-end connector 1141d. Any suitable cable connecting device could be used. The free ends of the cables of the other vertical brace assemblies of the two cell assemblies 1101a and 1101b, and the free ends of the horizontal brace assembles, are shown ready for connection to further cell assemblies. While the cell assemblies 1101a-b are shown connected using both the free ends of the cables of both the horizontal and vertical brace assemblies, it will be appreciated that neighbouring assemblies could be connected instead by joining together only horizontal brace assemblies, only vertical brace assemblies, and/or by joining horizontal and vertical brace assemblies.
[0088] FIG. 14 shows a top perspective view of two of the cell assemblies 1001 of FIG. 10 (labelled 1001a-b in FIG. 14). The cell assemblies 1001 are joined together by connecting the free ends of the cables 1040c of the brace assemblies 1040 using cable-end connectors 1040d. Any suitable cable connecting device could be used. The free ends of the cables of brace assemblies not used for connection are omitted for clarity.
[0089] FIG. 15 shows a top perspective view of two of the cell assemblies 1101 of FIG. 11 (labelled 1101a-b in FIG. 15). The cell assemblies 1101 are joined together by connecting the free ends of the cables 1140c of the vertical brace assemblies 1140 using cable-end connectors 1140d, and by connecting adjacent free ends of the cables 1141c of the horizontal brace assembles 1141 using cable-end connector 1141d. Any suitable cable connecting device could be used. The free ends of the cables of brace assemblies not used for connection are omitted for clarity.
[0090] It will be appreciated that cell assemblies may be secured together in other ways, for example by securing assemblies to a sheet of wire mesh spanning two or more assemblies and/or looping a tie wire around one or more cell assemblies.
[0091] FIG. 16a shows the fines barrier bag 720 of FIG. 7 before insertion into a cell, and with its top flap open. The bag 720 comprises a bottom 722, four upstanding sides 723 and a top flap 724. The top flap 724 is larger than the top opening of the bag to allow the flap 724 to be folded down the sides 723 of the bag when closed. The bag 720 is sized to fit snugly into a cell portion. Pressure of the panels of the cell keep the bag closed without the need for fastenings on the bag itself. Suitable bags are entirely made from a biodegradable material, such as sheep wool. FIG. 16b shows the bag 720 of FIG. 16a with the top flap 724 closed and folded down over the sides 723. As shown in FIG. 16b, the top flap 724 may be provided with a plurality of slits 725, through which live plants and/or plant seed can be inserted when the bag is filled and closed inside a cell. Optionally, the inside of the bag may be subdivided by a layer of geotextile material (not shown in FIG. 16a), for example to separate a first lower layer of large/coarse fill material from a second upper layer of finer fill material. For example, the first fill material may be rock pieces having a maximum diameter of 75 mm, and optionally a minimum diameter of 50 mm, and the second fill material may be rock pieces having a maximum diameter of 40 mm. Depending on the intended use of the cell assembly, the lid of the bag may be omitted.
[0092] FIGS. 17a-g show various perspective views of a cell assembly 1701 according to the invention being constructed and lifted into place, the figures collectively showing a sequence of steps for constructing and installing the cell assembly. FIG. 17a shows an open-topped rectangular forming frame 1702 placed on the ground 1703, within which the lower brace plates 1704 and tensioning cables 1705 of twelve brace assemblies are distributed. The forming frame defines an internal cavity 3.5 m?2 m?0.5 m (width?length?height), and is formed from four steel beams welded at the corners. Each brace plate 1704 is a stainless steel plate 8 mm?250 mm?250 mm, with a tensioning cable 1705 attached to its centre. Each tensioning cable 1705 terminates in a connection loop 1706 for attachment to a lifting device. FIG. 17b shows the frame 1702 and the partially formed brace assemblies overlaid with first 1710 and second 1720 continuous sheets of chain-link wire mesh. Each wire mesh sheet is Geobrugg? TECCO? high-tensile steel wire mesh G65/3 stainless. In the figures, the mesh diamonds are omitted on parts of the sheets for clarity (the overall outline of each sheet is shown in dot-dash lines where the mesh pattern is omitted. Other wire meshes could be used, including Al/Zn coated steel wire mesh, such as other Geobrugg? TECCO? mesh products. The first sheet 1710 has a width of 3.5 m and a length of 6 m; the second sheet 1720 has a width of 2 m and a length of 9 m. Each sheet is formed from a plurality of parallel, zig-zag shaped interlaced stainless steel wires that extend from one side to the opposite side in a general direction parallel to the ends of the sheet, thereby allowing the sheet to be wrapped around the faces of the cell assembly without bending the individual wires. In FIG. 17b the free ends of each sheet 1710, 1720 are folded out over the sides of the frame 1702. The brace plates 1704 of the bracing assemblies lie underneath the sheets 1710, 1720, with the tensioning cables 1705 protruding up through mesh openings. The sheets 1710, 1720 are laid across each over so that they overlap on the lower face of the cell assembly (on the ground 1703 inside the frame 1702), and are fastened together on the vertical edges 1707 of the cell assembly (inside the frame 1702) by stainless steel helicoil fastenings (not shown in FIG. 17b). FIG. 17c shows wire mesh panels 1730 (made from the same mesh material as the sheets 1710, 1720) inserted into the cell assembly forming baffles sub-dividing the internal volume of the cell assembly into twelve cells. In the figures, the cells are shown having different sizes; alternatively each cell may be approximately the same size. In FIG. 17c, the diamond pattern of the mesh of the sheets 1710, 1720 on the inside of the frame 1702 is omitted for clarity. The panels 1730 are fastened to each other and to the sheets 1710, 1720 where they intersect using stainless steel helicoil fastenings. Also shown in FIG. 17c are support tubes 1708 placed over the tensioning cables 1705 of the brace assemblies (provided to keep the cables upright when the cells are filled). FIG. 17d shows fill material 1740 (comprising rock pieces sized larger than the mesh openings) inserted into the cells. Fill material may be added and compacted by any convenient equipment, such as an excavator (not shown in FIG. 17d). FIG. 17d also includes arrows indicating that the free ends of sheets 1710, 1720 can now be folded across the top of the cells to close the cell assembly. It will be appreciated that support tubes 1708 may be left in place, or removed, once fill material is added to the cells. FIG. 17e shows one free end of sheet 1710 being drawn across the top of the cell. The end wire of the sheet is attached to a drawbar 1750 by a series of hooks 1751, the drawbar being connected to lifting equipment (such as an excavator or crane, not shown in FIG. 17d) by four chains 1752. In FIG. 17e, the end of the sheet 1710 being drawn across the top of the cell assembly is shown as an apparently solid sheet (so that features underlying the sheet cannot be seen through the openings of the wire mesh) for clarity. Each free end is drawn across in turn, first with the free ends of first sheet 1710 stretched across and joined by a first overlapping join (the length of overlap being about 1 m), and then the free ends of second sheet 1720 stretched across an joined by a second overlapping join (the length of overlap being about 1 m. The sheets are joined together using stainless steel helicoil fastenings (not shown in FIG. 17e). It will be appreciated that a shorter overlap could be used, reducing the amount of wire mesh required. The drawbar 1750 is used to stretch the sheets across the top of the cells, applying a tension of 15 kN to each sheet end. After fastening the sheet ends together, the tension along the length of each sheet was about 2.5 kN. Optionally, the first (lower) end of each sheet 1710, 1720 may be tensioned and fastened to one or more of the baffle panels 1730 to hold it in place while the second (upper) end of each sheet is stretched across and fastened to the first end by an overlapping join. Alternatively, the first end of each sheet 1710, 1720 may be drawn across and laid on the top of the cell assembly without fastening, before the second ends of the sheets are stretched across and fastened. Once all four free ends of the sheets 1710, 1720 are folded across and secured, and the brace assemblies completed by securing the upper brace plates (each being a stainless steel plate 8 mm?250 mm?250 mm with a centre through-hole for receiving a tensioning cable 1705 and held in place by a one-way clip on the cable; not shown in FIG. 17e) the cell assembly is complete and ready to be separated from the frame 1702. It will be appreciated that larger brace plates may be desirable, depending on the size of the cell assembly and the spacing of the bracing assemblies. The cell assembly 1701 has at least a double layer of wire mesh across all of its top (since the first and second sheets 1710, 1720 are each joined end to end), but only a relatively small area has a quadruple layer of wore mesh (i.e. where the two overlapping joins between sheet ends overlap each other). Most of the twelve bracing assemblies are positioned in a double layer area. FIG. 17f shows the completed cell assembly 1701 suspended from a lifting frame 1760. The lifting frame 1760 is made up of six rolled steel joists 1761 welded together and provided with twelve attachment points in the form of brackets 1762. The tensioning cables 1705 of the brace assemblies are attached to the brackets 1762 using end loops 1706, so that the cell assembly 1701 is suspended from the lifting frame 1760 by the brace assemblies. The lifting frame 1760 is attached to lifting equipment (a crane, not shown in FIG. 17f) by chains 1763. As shown in FIG. 17f, the wire mesh of the cell assembly 1701 is pulled tight around the fill material, distorting the shape of the assembly. It will be appreciated that lift assemblies could be used in place of brace assemblies. FIG. 17g shows the cell assembly 1701 being lifted at an angle so that the cell assembly 1701 can be place on a slope. The cell assembly is tilted to an angle by adjusting the angle of the lifting frame 1760, which in turn is angled by changing the lengths of the chains 1763 connecting the frame 1760 to the lift equipment. It has been found than an ability to tilt the cell assembly in a controlled manner is a particularly useful advantage facilitated by the lift arrangement of the cell assembly of the invention. In FIG. 17g, the cell assembly 1701 is shown fitted with lift assemblies rather than brace assemblies (i.e. upper brace plates have not been used). FIGS. 17f-g show that when mesh is tensioned around fill material, each face of the cell assembly may distort, especially when rocks are used as the fill material. In particular, all corners and/or edges of the cell assembly may be rounded, and/or faces may be curved and/or undulating. Nevertheless, the cell assembly retains its overall shape, having opposed upper and lower faces, opposed end faces and opposed side faces. It will be appreciated that the order of steps illustrated in FIGS. 17a-g is optionalone or more of the steps illustrated may be performed in a different order. For example, bracing assemblies could be moved into position after the sheets are arranged in the forming frame. In FIGS. 17a-17g, each continuous length 1720, 1720 is made from a single continuous sheet of mesh. It will be appreciated that a larger assembly could be formed (e.g. having a width of more than 3.5 m, such as 5 m or more) by joining two single continuous sheets side by side, preferably by an overlapping join. It will be appreciated that two sheets joined side to side would provide a wider continuous length, allowing formation of a wider cell assembly. It will be appreciated that when two sheets of china-link mesh having knotted ends are joined side to side by an overlapping join, the knotted ends of one sheet lie over or under the mesh of the adjacent sheet.
[0093] It will be appreciated that any cell design depicted in the figures may optionally include additional features described herein, such as one or more horizontal brace assemblies for tying together opposing side/end faces, and/or a stiffening mesh, e.g. in the form of a welded reinforcement mesh panel such as A393 mesh.
[0094] Coastal erosion prevention systems are often exposed to extreme forces, causing movement of even the largest of rocks commonly used for rock armour. In conventional sea defences, such forces tend to be damaging, weakening the system over time. However, a result of the fully integrated structure of the system of the present invention is that distortions of the system increases tension in the wire mesh, strengthening the structure. This is especially true when the mesh is formed from high tensile, (stainless) steel wire.
[0095] While the present invention has been described and illustrated with reference to particular embodiments, it will be appreciated by those of ordinary skill in the art that the invention lends itself to many different variations not specifically illustrated herein. Where in the foregoing description, integers or elements are mentioned which have known, obvious or foreseeable equivalents, then such equivalents are herein incorporated as if individually set forth. Reference should be made to the claims for determining the true scope of the present invention, which should be construed so as to encompass any such equivalents. It will also be appreciated by the reader that integers or features of the invention that are described as preferable, advantageous, convenient or the like are optional and do not limit the scope of the independent claims. Moreover, it is to be understood that such optional integers or features, whilst of possible benefit in some embodiments of the invention, may not be desirable, and may therefore be absent, in other embodiments.
