AU2013204510B2

AU2013204510B2 - Erosion control

Info

Publication number: AU2013204510B2
Application number: AU2013204510A
Authority: AU
Inventors: Daniel Charles Underwood; Lester George UNDERWOOD
Original assignee: Underwood Cos Holdings Pty Ltd
Current assignee: Underwood Cos Holdings Pty Ltd
Priority date: 2012-10-30
Filing date: 2013-04-12
Publication date: 2016-05-12
Anticipated expiration: 2033-04-12
Also published as: AU2013204510A1

Abstract

Erosion control panels 19 and 20 are shown to overlap in the region at 21. A post in the form of a stake or star picket 22 being approximately twice the depth of the panel, is driven through the panels into the sand below. The panels are formed from heat shrink plastics covered 3-8 mm steel mesh. The steel mesh is of approximately 20 cm to 30 cm on a side in square or rectangular configurations and is covered with heat shrink plastic of 1.2 p to 1.6 p thickness on a side of each of the panels before being shrunk onto the mesh. After the plastics has been shrunk onto the mesh the marginal top section is rolled and then the bottom section is folded. Posts 22 pass through the both panels simultaneously at the panel overlap. 6/4-4 fiAll

Description

1 EROSION CONTROL TECHNICAL FIELD [0001] THIS INVENTION relates to erosion control and in particular to a panel and panel assembly used to provide a protective barrier or baffle to the impact of erosion caused by water. BACKGROUND [0002] Erosion from wind and/or water continues to be a problem particularly in an age of anticipated rising sea levels, the risk to life and property is greater than ever. Properties adjacent beaches and streams are exposed to erosion that can rapidly remove part of the adjacent soil or sand thereby reducing the value of the property. In extreme cases this can expose the property to subsidence and risk of collapse by being undermined as erosion continues unabated. There have been a multitude of arrangements for control of erosion. The art may be described as "crowded" or a "developed" art. There have been fences, concrete walls, groynes, sandbag and rock barriers and a host of solutions involving some kind of barrier to block the removal of a land mass through erosion. [0003] At present it is usual to build retaining walls as permanent structures or where retaining walls are not provided, as in for example, emergency situations, sandbags are stacked in an effort to hold back surging tides and streams to thereby prevent the adjacent land from being exposed to sudden erosion. In the case of sand dunes it is not unusual to build paling fences and the like up high on the beachhead so that during extremely high tides and storms these fences afford some protection to the dunes. [0004] All the above arrangements work and are generally made to the prevailing standards so in this sense there is nothing wrong with them and they do not in any way lead to the conclusion that there is a specific obvious problem in need of solution. This means that the present invention does not arise through any deterministic relationship to the prior art but rather is the inventor's own inspiration in an individualistic way applying his mind to the general problem of erosion control, this being as an alternative to what is currently available, rather than an effort to deal with any specific recognised extant problem of the prior art. The present invention provides an alternative to present 2 proposals by providing a panel system that may be used as a temporary structure or a lost form for the protection of existing land against erosion and in other situations provide a mechanism whereby fill can build up and be retained behind the inventive structure either by being manually filled or by natural sedimentation. OUTLINE An erosion control panel assembly when used to control erosion caused by moving water comprising at least two prefabricated panels of heat shrink plastics covered steel mesh arranged adjacent and in contiguous relation, the so arranged panels being located in a region where erosion is to be controlled, upright posts holding the panels in operative position. [0005] In one aspect therefore, the present invention resides in an erosion control panel assembly when used to control erosion by water passing through the panels comprising at least two prefabricated panels of heat shrink plastics covered steel mesh arranged adjacent and in contiguous relation, the so arranged panels being located in a region where erosion is to be controlled, upright posts holding the panels in operative position. Preferably, the adjacent panels are self holding in overlapping relation and the posts pass through overlapping sections of adjacent panels to lock the panels together. Typically, the panels have post passage means for the posts to pass through the panels. [0006] Preferably, the panels have flow through passage means for flow of water through the panels and thereby aid in deposition of sediment behind the panels. [0007] In one preferred embodiment each panel has a top and a bottom edge formation, the top and bottom edge formations having post receiving outages aligned so that a post may pass through the outages and be located substantially on one side of the panel. Preferably, the outages comprise portions of the panel laterally displaced out of the plane of the panel. Preferably, the top is rolled over and the rolled over parts of adjacent panels can resiliently fit inside one another to hold the panels in end to end type configuration with marginal edges overlapping. The bottom is preferably folded flange-like to aid retention of the panel in the ground and aid in holding the panel upright during assembly.

3 [0008] Preferably the panel is a covered rigid steel mesh with the top edge formation comprises a folded over marginal edge section of the mesh panel. Preferably, the bottom edge formation comprises a marginal edge section of the mesh panel folded over to project from the plane of the panel. The folded over marginal edge section of the top of the panel may preferably be an inverted U-shape in profile comprising a few squares of the mesh rolled over parallel to the edge of the panel. The folded over marginal edge section of the lower edge of the panel may typically be an inclined flange comprising 2-3 squares of mesh. The mesh may be in the range of 6 cm - 30 cm on an edge. [0009] Preferably, each panel comprises a heat shrunk plastic coated steel mesh panel with the regions between the mesh being plastic film and tight across the mesh and there being provided water flow through passage means in a lower region of the panels and through the said plastic thereof. In the case of a plastic film the passage means may be cuts or slots in the film. [0010] In another aspect there is provided a method of erosion control comprising the use of prefabricated panels assembled in a panel assembly comprising said panels placed in end to end or overlapping relation to form a contiguous structure along a region where erosion is to be controlled, the panels being portable panels and assembled by hand and held in place by spaced posts driven through top and bottom portions of the panels and into the ground below, each panel having a top post locating section and a bottom post locating section so that the post passes through the panels at least twice, preferably, each panel comprises a heat shrunk plastic coated steel mesh panel with the regions between the mesh being plastic film and tight across the mesh and there being provided preferably, water flow through passage means in a lower region of the panels and through the said plastic thereof. BRIEF DESCRIPTION OF THE DRAWINGS [0011] In order that the present invention may be more readily understood and put into practical effect reference will now be made to the accompanying drawings which illustrate preferred embodiments of the invention and wherein: Figure 1 is an illustration showing a typical example of beach erosion; 4 Figure 2 is a drawing illustrating application of the present invention to the beach erosion situation of Figure 1; Figures 3 to 5 illustrate gradual buildup of sand behind a beach erosion barrier according to one embodiment of the present invention; Figure 6 is a side view illustrating installation of a erosion control panel according to one embodiment the present invention; Figure 7 is a part view illustrating a typical erosion control panel assembly of overlapping panels according to one embodiment of the present invention; Figure 8 is a section through a sand dune that has been recovered using an erosion control panel according to the present invention; Figures 9 illustrates in plan view another application of the present invention applied to a beach situation; Figure 10 illustrates application of the present invention to the a steep bank at beachside; Figures 11 and 12 illustrate application of the present invention to a creek; Figures 13 and 14 illustrate application of the present invention to the eventual straightening of a creek; Figure 15 illustrates application of the present invention to another creek; and Figures 16 to 19 illustrate an erosion control panel according to one preferred embodiment of the present invention. METHOD OF PERFORMANCE [0012] Referring to the drawings and initially to Figure 1 there is illustrated a beach side situation 10 where wave action at 11 is causing noticeable erosion at 12 adjacent to the home 13. Clearly the home 13 is at risk of being undermined by the wave activity at 11 and continued erosion. [0013] In order to alleviate the problem of Figure 1 the present invention employs erosion control panel 14 as part of an assembly of these panels shown installed at 15. It is installed out from the region of erosion 12 left by the wave action shown in Figure 1. Thus this blocks and baffles the waves so that they impinge on the panel assembly.

5 [0014] The erosion control panel assembly in this case is installed parallel to the line of the beach and multiple panels 14 are installed in contiguous fashion using spaced stakes, pickets or posts 16 driven through the panels as will be described in further detail below. [0015] The typical high watermark is shown in broken line at 17 but it will be appreciated that depending upon the prevailing weather conditions and storm activities storm surges will create situations that will increase the erosion activity in the event present invention was not being used. [0016] As illustrated in Figure 2 the erosion control panel 14 and the system of the present invention provides a baffle to wave activity although water may pass over the top of the panels, it serves to carry sand behind the panels so this is a useful feature. Lower panels may be used to make sure this happens. The panels include passage means for the purpose of allowing water to pass back through the panels while sand carried by the water is trapped behind the panels as shown at 18. The passage means may be slots or any kind of opening typically near a lower region of the panels. [0017] It will be appreciated that the sand can therefore build up in the region 18 and eventually create a restored situation as shown in the following Figures 3 and 4. While a fixed panel 14 positioned as shown in Figures 1 to 5 it will be appreciated that the panels may be raised or lowered or panels of different height may be used and progressively changed in order to modify the final outcome. Also panels may be staggered along the beach at different heights, again to provide a varying outcome in the final effect depending upon the prevailing weather and conditions and what may be required in terms of topology or is possible hydraulically. [0018] Figures 1 to 5 are merely exemplary and the outcome may be quite different depending upon the particular environment. [0019] For example, the approach to location and positioning of the beach erosion control panels may vary considerably as may the panel depth selected in a particular situation or circumstance. In one instance a relatively shallow panel may be chosen initially and then that panel removed once it is covered and a deeper panel inserted in its place. The reverse may be case in other situations. In some cases the panels may be applied to the sand surface or in other cases a shallow trench may be dug and the panel located in the trench up to a desired level so that this is another way of 6 varying the panel height as compared to the water level anticipated at the site. Other surrounding circumstances might require a different set up to give a desirable result according to the circumstances. The panels according to the invention are both easily installed and relatively easily removed so that in the event a first set up is not as effective as planned adjustment is relatively easy compared to other prior art solutions. This arrangement may be tweaked to improve efficacy. [0020] As can be seen in Figure 4 the top of the panel is at this stage covered by sand, the panel could be raised slightly or additional panels inserted upstream or downstream of that existing panel and in this sense the panels can be used temporarily or other circumstances as illustrated in Figure 5, there the erosion control panels remain permanently in place and are lost as part of the process. Panels of different height may be staggered on the beach or exchanged as the erosion comes under control, as might also be required for aesthetics if the beach is to be used for recreation. The present invention has great flexibility due to its semi permanent nature. [0021] Figures 6 and 7 illustrates the typical mode of installation and assembly of panels, where panels 19 and 20 are shown to overlap in the region at 21. A post in the form of a stake or star picket 22 being approximately twice the depth of the panel, is driven through the panels into the sand below. The stake is driven in at the overlap and secures the panels together. The panels are identical but the rolled top is resilient so that one can expand to allow the other to fit snugly inside. [0022] As shown in Figure 6 the panels are located on top of the sand but the broken line at 23 indicates that in some circumstances it may be desirable to dig a trench and locate the bottom marginal region of the panels in the sand. [0023] As can be seen each panel has an overturned or rolled top section at 24 and a flange, in this case, an inclined bottom section at 25, with these extending along the tops of the panels and bottom of the panels as shown. This has the purpose of adding rigidity, for aiding in locating panels in line in overlapping configuration so they hold together and also for the purpose of aligning and locating the stake 22 in position as shown. [0024] The sake 22 is simply driven through into the ground as illustrated by the operator at 26. The panels may be secured to the stakes using any suitable means as cable ties illustrated at 27 and 28 in Figure 7. The stake is T-shaped and driven down until its top is in contact with the top 7 surface edge 29 of the panels as illustrated in Figures 1 to 5. It will be appreciated that the stake passing through the overlap also serves to lock the adjacent panels together so it is usual to use a stake at each panel-to-panel juncture. [0025] Referring now to Figure 8, a further aspect of a preferred form of the invention is illustrated, in this case as the sand has built up to a certain height a fabric runner of mesh, shade cloth, rope or other material is laid on top of the sand so as to eventually become buried as shown at 30. These reinforcing runners can be positioned right along the beach at spaced intervals and these serve as insurance in the event of very heavy wave action that might occur in the case of storms or otherwise to further strengthen the erosion control panels and inhibit the removal in the case of extra turbulent activity on the outside of the panels. [0026] Referring now to Figure 9 there is illustrated a beach 31 where erosion control assemblies 32, 33, 34 and 35 have been positioned staggered along the beach in order to control and manage the deposition of sand at 36, 37, 38 and 39 along the beach 31. Each of the control assemblies 32, 33, 34 and 35 are made up of panels 14 assembled and shown and in each case the panel assembly is generally U-shaped in plan view. In this case at 900 corners, various angles of these turned sections may be used at one or both ends depending on the requirements for retaining the sand deposited by the water passing across and around the control panels. This drawing serves to illustrate the flexibility of the present invention, for example, if there is desired to make a flat walking region or staggering of the resulting dunes after a few months the effect may be revised and the panel positions adjusted. [0027] Referring to Figure 10 there is illustrated another embodiment of the invention used along a beach 40 where a building 41 is located on top of and adjacent to a relatively steep bank 42. Erosion control panel assembly 43 is shown where multiple panels 14 have been placed in position as shown previously right along the steep bank 42 and each of the panels are staked in place as previously shown and in overlapping configuration formed as a corner at 44. In this case after the panel assembly 43 has been located in position the bank 42 has been backfilled behind the erosion control assembly so in this case the erosion control assembly serves as an initial retaining wall for backfilled sand at 45 but also as any storm surges or high tide levels cross over the top edge 29 of the assembly retaining sand, this will be deposited on the bank as water passes back through the 8 passage slots 46 which are located at spaced intervals along the panels as in previous embodiments. [0028] The previous embodiments relate to use of the present invention along a beach whereas the present invention has other applications including along creeks and these are illustrated in the drawings of embodiments Figures 11 through 15. In Figure 11 there is illustrated a creek 50 having a water flow direction as illustrated in Figure 12 and an eroding bank 51 and it is desirable to control and inhibit the erosion of the bank 51 and also to reclaim part of the stream adjacent to the bank 51. If it was desirable to reclaim a region adjacent the bank 51, the control panel assembly is accordingly placed very close to the bank 51. However, as illustrated in Figure 12 it is desirable to deposit silt or other material when the creek is in flood between the panel assembly as illustrated in Figure 12 and the existing bank 51 in order to reclaim this region. Thus a panel assembly 52 is located in position using stakes 22, as previously illustrated the panels have flow through slots located in the panels and the panel assembly has an upstream end at 53 and a downstream end at 54 against the bank 51. The assembly is spaced from the bank 51 at 53 thus water is able to flow into that region and silt it carries trapped while pressure against the assembly 52 being washed away is ameliorated by the slots 46 or other openings which may be located in and through the material making up the panels. It will be appreciated that it is a simple manner in the case of a mesh covered with plastic film to add flow through capacity by simply cutting more holes or slits. [0029] As a consequence of these types of arrangements a stream may be redirected and eventually straightened as illustrated schematically in Figures 13 and 14. [0030] It will be appreciated that in relation to streams of this kind that there would be progressive use of the panel assembly according to the present invention so that over time panels could be adjusted in position so that the panels form the creek as shown in Figure 14 by the straight sections in solid line which represent the position of panels at that time. [0031] Figure 15 shows a creative arrangement of panel assemblies 54, 55, 56, 57, 58, 59 and 60 adapted to reclaim and divert parts of a stream 61 from the position illustrated in broken line to position illustrated in Figure 15.

9 [0032] While each panel 14 may be of any particular configuration arrangement, including sheet moulded from plastics, in a particularly preferred embodiment of present invention the panels are formed from heat shrink plastics covered steel mesh as exemplified by Figures 16 to 19, the mesh could be 3-8 mm steel mesh. In Figures 16 to 18 an erosion control panel 62 is illustrated breakaway in two directions to illustrate that the panel may be of any length or any depth within practical reasons for practical utility. In the preferred embodiment the steel mesh is of approximately 20 cm to 30 cm on a side in square or rectangular configurations and is covered with heat shrink plastic of 1.2 p to 1.6 p thickness on a side of each of the panels before being shrunk onto the mesh. After the plastics has been shrunk onto the mesh the marginal top section is rolled and then the bottom section is folded. Of course this could be reversed. The panel detail is illustrated in Figure 19. In the drawings illustrated the water flow through slots have not been cut but these are simply cut as vertical lines as illustrated in broken line at 63 in Figure 19. These could be spaced at any suitable interval depending upon flow rate required for a particular application and so could be cut on site. They may be evenly spaced or vary along the assembly depending on the desired flow. As illustrated in Figure 19 the plastic is drawn drum tight across the welded mesh form. [0033] Whilst the above has been given by way of illustrative example of the invention many variations and modifications will be apparent to those skilled in the art without departing from the broad ambit and scope of the invention as herein set forth. In addition in the present description and claims words "comprised", "comprising", "including" and similar words used herein are non-limiting and are used in the non-exhaustive inclusive sense, that is to say they do not mean "made up of' but rather "include" meaning that extra features may be added to the combination referred to by these terms and still fall within the broad ambit and scope of the invention.

Claims

1. An erosion control panel assembly when used to control erosion by water passing through the panels comprising at least two prefabricated panels of heat shrink plastics covered steel mesh arranged adjacent and in contiguous relation, the so arranged panels being located in a region where erosion is to be controlled, upright posts holding the panels in operative position.

2. An erosion control panel assembly according to claim 1 wherein the adjacent panels are self holding in overlapping relation and the assembly further comprises posts passing simultaneously through the adjacent panels to lock the panels together.

3. An erosion control panel assembly according to any one of the preceding claims wherein the panels have post passage means for posts to pass through the panels.

4. An erosion control panel assembly according to any one of the preceding claims wherein the panels have flow through passage means for flow of water through the panels and thereby aid in deposition of sediment behind the panels.

5. An erosion control panel assembly according to any one of the preceding claims wherein each panel has a first side and an opposite side, a top edge formation and a bottom edge formation, the top and bottom edge formations having post receiving outages aligned so that a post may pass through the outages and be located substantially on one side of the panel.

6. An erosion control panel assembly according to any one of the preceding claims wherein the outages comprise portions of the panel laterally displaced out of the plane of the panel.

7. An erosion control panel assembly according to any one of the preceding claims wherein the or each of a said panel has a top and the top of the panel is rolled over and rolled over parts of adjacent panels can resiliently fit inside one another to hold the panels in end to end type configuration with marginal side edges overlapping. 11

8. An erosion control panel assembly according to any one of the preceding claims wherein the or each of a said panel has a bottom edge of the panel which is folded flange like to aid retention of the panel in the ground and aid in holding the panel upright during assembly.

9. An erosion control panel assembly according to any one of the preceding claims wherein the panel is a covered rigid steel mesh with top edge formation comprises a folded over marginal edge section of the mesh panel.

10. An erosion control panel assembly according to any one of the preceding claims wherein the bottom edge formation comprises a marginal edge section of the mesh panel folded over to project from the plane of the panel.

11. An erosion control panel assembly according to any one of the preceding claims wherein the folded over marginal each section of the top of the panel is an inverted U-shape in profile comprising squares of the mesh rolled over parallel to an upper edge of the panel.

12. An erosion control panel assembly according to any one of the preceding claims wherein the folded over marginal edge section of the lower edge of the panel comprises an inclined flange comprising squares of mesh.

13. An erosion control panel assembly according to any one of the preceding claims wherein each panel comprises a heat shrunk plastic covered steel mesh panel with the regions between the mesh being plastic film and tight across the mesh and there being provided water flow through passage means in a lower region of the panels and through the said plastic covering thereof.

14. A method of erosion control to control erosion by water comprising the use of prefabricated panels assembled in a panel assembly according to any one of claims 1-12 comprising, said panels placed in end to end or overlapping relation to form a contiguous structure along a region where erosion is to be controlled, the panels being portable panels and assembled by hand and held in place by spaced posts driven through top and bottom portions of the panels and into the ground below, each panel having a top post locating section and a bottom post locating section so that the post passes through each panel at least twice. 12

15. A method of erosion control according to claim 14 wherein each panel comprises a heat shrunk plastic covered steel mesh panel with the regions between the mesh being plastic film and tight across the mesh and there being provided water flow through passage means in a lower region of the panels and through the said plastic thereof.