GB2083115A - Reinforced flexible shutters - Google Patents

Abstract

Reinforcing shutters for protecting river banks and other land areas adjacent water comprise two layers joined at spaced locations so that, when the shutters are filled e.g. with sand or a concrete mix, the resulting protective mattress contains unfilled areas where the layers are in contact. Preferably, the layers (110, 111) have reinforcing filaments (112) in the form of steel wire cores (115) in ropes (114) in the form of two mutually-crossing spaced series attached to the layers (110, 111) at intervals so as to define cruciform areas. <IMAGE>

Description

SPECIFICATION Reinforced flexible shutters This invention relates to reinforced flexible shutters, that is, structures of flexible material which serve for the controlled placement of filler materials, e.g. sand, or settable compositions, e.g. concrete mixes, so that the combination of the shutter and the filler or composition, when the latter has set, becomes a fixed mattress-like structure. Reinforced flexible shutters and fixed mattress structures made using them serve to minimize the scouring effect of water action on the beds and banks of water-flow channels, such as rivers, estuaries, canals, reservoirs and the sea. In particular, such structures provide protection for sea and like defences, where the severity of the water action is increased by tidal and storm waves as well as by waves created by shipping and other marine craft.

Flexible shutters for receiving and retaining filler material, concrete and other settable compositions for these and analogous purposes are already known and commonly consist of complex woven or other geotextile fabric structures, comprising two interconnected webs which define a double-skin blanket-like structure which conforms to the shape of the ground or other solid material on which it is placed, e.g. a marine foreshore or river bank, and can receive and retain a liquid concrete mix, which sets in the space between the interconnected webs.

For instance, a protective facing of this general kind, having its two layers interconnected at places which form areas not reached by the settable material on installation, is disclosed in GB Patent Specification 1111453. It is also known to lay sandfilled mattresses on island banks, which are made of fabric woven double at spaced locations in the form of longitudinal tubes. These tubes are closed transversely at intervals and the resultant long pockets or cells are filled with sand as the mattresses are located in place.

These woven or other fabric structures have the general disadvantage of being liable to wear, weakening and damage, in time, because they are natural or man-made organic materials, for example, jute, nylon or polypropylene. These materials are adversely affected by the wear caused by constant contact with water or sand, gravel or other solids in motion, by biodegredation caused for instance by bacterial action or ultraviolet radiation and they are often prone to damage through accident or vandalism.

The present invention provides a reinforced flexible shutter construction which minimises or avoids some or all of these disadvantages.

According to the present invention, a flexible shutter comprises two generally co-extensive layers or webs of flexible material capable of being mutually separated so as to define between them a fillable space which can receive and retain a filler material introduced between the layers, opposed regions in the respective webs being interconnected by mutual attachment at intervals along reinforcing filaments extending between the webs.

According to one preferred feature of the invention, the layers or webs are woven and preferably the reinforcing filaments are attached to them by the weft threads, the warp threads or, preferably, by both the weft and the warp threads. Such a structure can most conveniently be made by locating the reinforcing filaments, for instance a plurality of such filaments extending mutually parallel and equidistant, in either or, preferably, both of the warp and weft directions, as the two layers are woven simultaneously or separately, the attachment being made by weaving the reinforcing filaments into the two webs as the latter are made.

According to another preferred feature the reinforcing filaments, which are advantageously in the form of ropes, suitably having a diameter of 12 to 15 mm (at least), are themselves reinforced by metal cores, such as steel wires located axially. Thisfeature greatly increases the strength, cohesion and wear-resistance of the flexible shutter structures and also aids considerably in minimizing the effect of degradative factors and vandalism.

Preferably, a flexible shutter according to the invention has a series of reinforcing filaments which extend fully across the shutter in an equispaced arrangement parallel to the warp or weft direction or two series of such reinforcing filaments in a mutually-crossing arrangement, each series extending fully across the shutter in equispaced arrangements and respectively the warp and weft direction.

The opposed regions of the layers are attached to and thus by the filaments along discrete lengths located at the same aforesaid intervals along the filaments, so that the layers or webs are interconnected over the full extent of the structure along regularlyarranged interrupted lines. In an especially preferred embodiment, the attachment is effected by weaving loops in the webs, through which the reinforcing filaments pass, so as to attach themselves to the webs and to attach the webs together. Moreover, the regularly-spaced attachments in two mutuallycrossing directions, as is most preferred, defined cross-shaped portions where the webs are attached together.When installed and filled, e.g. with a filler such as sand or, more preferably, a settable composition such as concrete, the completed structure comprises continuous filled regions extending across the structure in one or both directions parallel to and between the unfilled regions represented by the interconnected locations and further filled regions merging with the first-mentioned regions and extending across the structure transversely of and between respective columns of unfilled regions.

While interconnection by the weft and/or warp threads is preferred, particularly as a result of simultaneous weaving of the respective webs and their interconnection to and by the filaments, the structure according to the invention can be made by simpler techniques, if desired. For instance, it is possible to lay lengths of reinforcing filaments, e.g. steel cored hemp ropes, in an equispaced and parallel array comprising one or, preferably, two mutually crossing series of such filaments, between separate woven layers and produce the desired interconnection by stitching through the layers and the ropes along the lines of the latter, interrupting the stitching at regular intervals.

In order that the invention may be readily appreciated, preferred embodiments are briefly described below, by way of illustration of the invention, in conjunction with the accompanying drawings, in which: Fig. 1 shows a diagrammatic perspective view of one form of the flexible shutter of the invention, with parts omitted to reveal the construction; Fig. 2 shows the flexible shutter of Fig. 1 when filled and installed in place; Fig. 3 shows a view similar to Fig. 1 of a flexible shutter having its webs interconnected in lines parallel to the warp threads and also lines parallel to the weft threads; Fig. 4 shows a view similar to Fig. 2 of the flexible shutter of Fig. 3 when filled and installed in place; Fig. 5 shows diagrammatically a cross-section through a flexible shutter of this invention.

Fig. 1 shows a flexible shutter structure comprising two superposed and generally co-extensive fabric layers of webs 10, 11, woven for instance from a polyamide (e.g. "Nylon") or polypropylene yarn.

These webs 10, 11 are interconnected at spaced intervals both along and across the shutter structure, as indicated by the rows and columns of elongated and aligned areas 12 indicated in broken lines. Each row of interconnected areas 12 follows the direction of a reinforcing filament 13 interposed between the webs 10, 11 and extending fully across the shutter structure in that direction. Each column of intercon nected areas 12 is formed at the corresponding lengths of adjacent filaments 13, which are mutually equidistant and parallel. Each filament 13 consists of a multi-strand rope 14 having a steel wire or other reinforcing core 15.

The flexible shutter is preferably made by laying the ropes 14 between the webs 10,11 as the latter are being weaved, so that interconnection of each web 10,11 to the reinforcing ropes 14, and therefore interconnection of the two webs 10, 11 together, occurs by attaching the ropes 14 to the weft threads of the webs 10, 11. The complete shutter has the webs 10, 11 interconnected at their respective edges, except that means may be provided at or adjacent one or more edges of the structure to enable it to be filled in use.

In use, the structure is installed as illustrated diagrammatically in Fig. 2, where the shutter is shown generally at 16, laid upon the sloping bank 17 of a river, reservoir or other body of water. The broken line 18 indicates a possible location for the level of the body of water. The filling within the structure 16 causes it to expand in thickness, except at the interconnected areas 12, so that, with the length direction of these areas 12 arranged as shown, the installed structure 16 consists of elongated bolster-like sections 19 extending parallel to one another between the rows of the areas 12 and connected transversely, i.e. parallel to the bank 17, by further sections 20 formed between the columns of the areas 12.In addition to providing better resistance to the various adverse effects met with in use, the steel reinforce ments or cores 15 (Fig. 1) in the ropes 14 will resist damage e.g. through vandalism of the exposed parts of the structure and also ensure its integrity even when prolonged exposure and wear begin to disrupt the reinforcing ropes 14 or even the interconnected areas 12.

In the preferred form of flexible shutter shown in Figs. 3 and 4, the various parts are indicated by references which are increased by 100 in comparison with the references identifying the correspond ing parts included in Fig. 1 and 2. In Fig. 3, therefore, two superposed layers or webs 110,111 are woven from a polyamide or polypropylene yarn, for instance. These webs 110, 111 are interconnected both along and across the shutter structure, as indicated by the rows and columns of aligned cruciform areas 112 indicated in broken lines. Each row of areas 112 follows the direction of one member of a first series of reinforcing elements 113 between the webs 110, 111 and each area 112 is located where that element 113 is crossed by the elements 113 forming the other series of such elements 113. Each consists of a rope 114 having a steel wire or other reinforcement 115. As shown in Fig. 5, the webs 110, 111 are desirably joined to and by the elements 113 by the latter passing through related loops 121,122 woven into the mutually-facing sides of the respec tire webs 110,111.

As shown in Fig. 4, in use, the shutter 116 of Fig. 3 is laid, e.g. on a river bank 117 having a water level 118. The filling within the shutter 116 causes itto expand so that the webs 110,111 are spaced apart except at the cruciform areas 112 of interconnection.

Continuous lines or bands 119, 120 where the shutterfilling is located extend in two mutually-crossing directions between the rows and columns ofthe cruciform areas 112.

Claims (14)

1. A flexible shutter, which comprises two generally co-extensive layers or webs of flexible material capable of being mutually separated so as to define between them a fillable space which can receive and retain a filler material introduced between the layers, opposed regions in the respective webs being inter-connected by mutual attachment at intervals along reinforcing filaments extending between the webs.

2. A flexible shutter according to claim 1, wherein the layers or webs are of woven fabric.

3. A flexible shutter according to claim 2, wherein the reinforcing filaments are attached to the layers or webs by some or all of either or both of the warp threads and the weft threads.

4. A flexible shutter according to claim 3, wherein a series of reinforcing filaments are located so as to extend mutually parallel and equidistant in the warp or weft direction.

5. A flexible shutter according to claim 3, wherein two series of reinforcing filaments are located so as to extend mutually parallel and equidistant respectively in the warp and weft direc tions.

6. A flexible shutter according to any of claims 2 to 5, wherein the reinforcing filaments are reinforced by metal cores.

7. Aflexible shutter according to claim 6, wherein the reinforcing filaments comprise ropes having steel wire cores.

8. A flexible shutter according to any of claims 2 to 7, wherein the reinforcing filaments extend fully across the layers or webs and the latter are attached to and by the reinforcing filaments along discrete lengths thereof.

9. A flexible shutter according to claim 8, wherein the reinforcing filaments comprise two mutually-crossing series and the layers or webs are attached to and by them in an arrangement of rows and columns of cruciform areas of interconnection.

10. A flexible shutter according to claim 8 or 9, wherein the reinforcing filaments pass through loops woven in the layers or webs.

11. A flexible shutter according to claim 8 or 9, wherein the reinforcing filaments are stitched to the layers or webs.

12. A flexible shutter according to claim 1, substantially as described with reference to Figs. 1,2 and 5 of the accompanying drawings.

13. A flexible shutter according to claim 1, sub- stantially as described with reference to Figs. 3 to 5 of the accompanying drawings.

14. An area of land adjacent water, when protected from erosion by a filled flexible shutter according to any preceding claim.