ELEMENT AND INSTALLATION FOR STABILIZING AN UNDERWATER PLOT

Abstract

TITLE OF THE INVENTION: ELEMENT AND INSTALLATION FOR STABILIZING AN UNDERWATER PLOT An element for stabilizing an at least partially underwater plot, at least at times, comprises a base (102) comprising several arms (103) angularly offset from each other around a central axis (X). Each arm (103) has a proximal part (110) and an end (111) which extends this proximal part (110). Notches (115) in the base (102) are located between the arms (103) and have a shape generally complementary to the ends (111) of the arms (103). Figure for the abstract: figure 2

Description

Title of the invention: ELEMENT AND INSTALLATION FOR STABILIZING AN UNDERWATER PLOT Technical field of the invention

[0001] The present invention relates to the field of combating coastal erosion, the effects of swell and other phenomena likely to act on, alter and / or modify seabeds and / or installations that are at least partially submerged permanently or at times, for example due to tides.

[0002] More specifically, the invention relates to a stabilizing element for a plot that is at least partially underwater at least at times, as well as an installation comprising several examples of this stabilizing element.

[0003] For example, the invention can be applied to the stabilization of a coastal beach, the stabilization of an underwater bottom such as a sandy bottom, the stabilization of a cliff foot and / or the stabilization of a dike armour foot. State of the art

[0004] Underwater dikes made of stone blocks extracted from quarries or made of geosynthetic tube systems, which are elongated bags filled with sand, have been proposed. Geosynthetic tubes do not constitute a long-term and therefore satisfactory solution, because they are very vulnerable due to their fragility in the face of navigation incidents such as impacts from boats, boat anchors, and various floating objects.

[0005] The warming of the Earth's atmosphere is becoming increasingly a reality, the multiple consequences of which include a rise in sea and ocean levels, as well as an increase in the frequency and violence of storms.

[0006] Such consequences of global warming on a terrestrial scale raise fears of a significant worsening of coastal erosion phenomena and changes in the nature and very functioning of these coastal erosion phenomena.

[0007] As a result, an old need is still relevant. This is the need to make progress in the fight against coastal erosion, the retreat of the coastline, the effects of swell and other phenomena likely to act on, alter and / or modify seabeds and / or installations that are at least partially submerged permanently or at times, for example due to tides. Summary of the invention

[0008] A piece of coastline alternately underwater and in the open air with the repetition of the cycle of high tide then low tide is an example of a piece of land at least partially underwater at least at times. A dike foot is another example of a piece of land at least partially underwater at least at times.

[0009] A stabilizing element for a plot that is at least partially underwater at least at times comprises a base comprising several arms angularly offset from each other around a central axis. One end of each arm and notches in the base, between the arms, have generally complementary shapes, which makes it possible to partially fit neighboring stabilizing elements into each other. Brief description of the figures

[0010] Other advantages and characteristics will emerge more clearly from the following description of a particular embodiment of the invention, given by way of non-limiting example and represented in the appended drawings, among which:

[0011] [Fig-1] is a perspective view of a stabilizing element according to one embodiment of the invention, in place on an underwater bed,

[0012] [Fig.2] is a top view of the stabilizing element visible in [Fig.l],

[0013] [Fig.3] is a bottom view of the stabilizing element visible in Figures 1 and 2,

[0014] [Fig.4] is an axial sectional view of the stabilizing element visible in Figures 1 to 3,

[0015] [Fig.5] is a side view in which the stabilizing element visible in Figures 1 to 4 is immersed and permanently on an underwater bed, and

[0016] [Fig.6] is a schematic view, from above, in which a permanent stabilization installation on an underwater bed comprises a grouping of several joined copies of the stabilization element of figures 1 to 5. Description of the embodiments

[0017] In [Fig.l], a stabilizing element 101 according to one embodiment of the invention rests on an underwater bed F to be stabilized, such as an underwater expanse of sand subject to intermittent sea currents.

[0018] A base 102 of the stabilizing element 101 comprises several generally identical arms 103, which connect to a central portion 104.

[0019] When the stabilizing element 101 is in place for example on an underwater bed F to be stabilized, its base 102 including the arms 103 rests on this underwater bed F, which is the case in [Fig.l].

[0020] In the following and in the appended claims, the terms “bottom”, “top”, “below”, “above” and “lateral”, as well as analogous terms, consider that the stabilizing element 101 is definitively installed and operational at its final destination location and that its base 102 rests on a substantially horizontal surface such as the seabed F. Of course, according to another possible use situation, the stabilizing element 1 permanently rests on an irregular surface and / or slope of a plot to be stabilized.

[0021] The central portion 104 comprises a projecting portion 105, which projects upwards, relative to the arms 103.

[0022] The arms 103 are arranged in a star shape and angularly offset from each other around a central axis X.

[0023] As can be clearly seen in Figures 2 and 3, the arms 103 are radial arms, each of which extends along a radial axis R perpendicular to the central axis X.

[0024] The arms 103 are regularly distributed around the central axis X. In other words, the angle between the two arms 103 of a pair of consecutive arms 103 is generally the same, regardless of the considered pair of consecutive arms 103. The angle α between two consecutive arms 103 of any pair of consecutive arms 103 is generally equal to 360° divided by the number n of arms 103.

[0025] In the embodiment shown, the number n of arms 103 is five, and the angle α between two consecutive arms 103 of any pair of consecutive arms 103 is generally equal to 72°.

[0026] In the embodiment shown, the arms 103 are five in number and have the same length. According to a first alternative embodiment, the number n of arms 103 may be different from five. According to a second alternative embodiment, the arms 103 have different lengths from each other. According to a third alternative embodiment, the number n of arms 103 is different from five and the arms 103 have different lengths from each other.

[0027] Each arm 103 has a proximal portion 110 which connects to the central portion 104. Each arm 103 has a tip 111 which extends its proximal portion 110. Each tip 111 has an edge 112 having two sides 113 which form between them a projecting angle pointing in the direction opposite to the central portion 104.

[0028] The base 102 comprises notches 115 that are identical to each other. Each notch 115 is located between two consecutive arms 103 that delimit it. Each notch 115 has a shape that is generally complementary to any end 111. Each notch 115 comprises an edge 116 having two sides 117 that form between them a re-entrant angle pointing towards the central portion 104. Each side 117 has generally the same length as each side 113.

[0029] As can be seen in Figures 3 and 4, the underside 118 of the base 102 is provided with pyramids 119 which project downwards. The pyramids 119 form a relief for anchoring the stabilizing element 1 in the seabed F.

[0030] As can be clearly seen in [Fig. 4], the central portion 104 is hollow and crossed from one side to the other by a central empty space 120. This central empty passage 120 has the form of a rising passage which opens upwards, into the top of the projecting portion 105, and which opens downwards, into the bottom 118 of the base 102.

[0031] The central empty space 120 is flared so that its passage section decreases as one ascends. The passage section of the central empty space 120 is thus greater at the lower end thereof than at an upper part that this central empty space 120 comprises above the center of gravity G of the stabilizing element 1. When the stabilizing element 1 is lowered or descends under the effect of its own weight in water to the plot to be stabilized, water is thus caused to rush into the central empty space 120, through the lower end thereof, and to form a current passing through the stabilizing element 1, which tends to oppose a significant tilting or even a turning over of the stabilizing element 1.

[0032] The projecting portion 105 comprises lateral conduits 125 connecting the central empty space 120 with the space outside the stabilizing element 101.

[0033] When the stabilizing element 101 in place on the underwater bed F is submerged, the central empty space 120 filled with water forms a refuge for underwater fauna. This underwater fauna can use the lateral conduits 125 to enter and exit the central empty space 120.

[0034] In [Fig.5], the stabilizing element 101 is in place on the seabed F. Its base 102 covers a portion of this seabed F and thus protects this portion against the various currents that may occur in the seawater E. In the case where the stabilizing element 101 is only partially submerged, its base 102 also protects the covered portion against waves.

[0035] The stabilizing element 101 is made of concrete. This concrete is unreinforced or it is reinforced for example by fibers such as glass fibers, carbon fibers, polymer fibers and / or by other reinforcements which are chosen from those which do not swell in the presence of chlorides if the stabilizing element 1 is intended for a marine or oceanic environment.

[0036] According to a variant, the stabilizing element 101 comprises an envelope such as a shell or a lost formwork, this envelope containing concrete molded therein and / or one or more granular materials such as sand, gravel, stones, pebbles and / or a mixture of several of them.

[0037] Preferably, the stabilizing element 101 is manufactured at or near the location of the plot that it will be used to stabilize. This avoids the need to transport large and heavy elements over long distances, which is not the case most of the time if an underwater dike is made from blocks of stone extracted from quarries.

[0038] In [Fig.3], an installation 130 for stabilizing a larger plot of the bottom submarine F comprises two adjoining rows of stabilizing elements 101 themselves adjoining, which rest on this underwater bed F.

[0039] In each row, it is repeated that one end 111 of one of two consecutive stabilizing elements 101 is fitted into a notch 115 of the other stabilizing element 101 among these two consecutive stabilizing elements 101. Furthermore, one end 111 of each stabilizing element 101 of the row on the right in [Fig.6] is fitted into a notch 115 of a stabilizing element 101 of the row on the left in [Fig.6].

[0040] Thanks to the end fittings 111 in notches 115, the stabilizing elements 101 of the stabilizing installation 130 lock each other against pivoting on themselves, while blocking each other in horizontal translation.

[0041] In [Fig.6], the stabilization installation 130 only comprises five stabilization elements 101 for the sake of clarity.

[0042] As can be seen in [Fig.6], the majority of the plot where the stabilization installation 130 is located is covered by the stabilization elements 1. There are certainly uncovered areas 140 between the stabilization elements 101. However, these uncovered areas 140 are few in number and each have a small surface area. It is very difficult for a water current, or for breaking wave eddies, to reach them due to their small size and their depth relative to the tops of the arms 103. In addition, and depending on the nature of the supporting soil, an anti-scour mat can be laid beforehand, avoiding losses of supporting soil.

[0043] Two consecutive stabilizing elements 1 of the stabilizing installation 130 may not be exactly at the same height and / or may not have the same inclination relative to the horizontal, depending on the topography of the plot to be stabilized, that is to say depending on possible spatial variations in relief at the level of this plot. The stabilizing installation 130 forms a protective shell which is thus adaptable to possible spatial variations in relief in the plot to be stabilized. As if it were formed of scales articulated to each other, this protective shell is also adaptable to possible changes over time in possible spatial variations in relief in the plot to be stabilized, compared to a concrete screed under which a hollow can form and enlarge over time.

[0044] The projecting portions 105 in the stabilization installation 130 act collectively against possible waves, which they effectively break. The projecting portions 105 in the stabilization installation 130 provide mutual protection of the stabilization elements 101 in the installation 130 against waves, in a manner comparable to the mutual protection that trees in a forest provide against winds. The projecting portions 105 in the stabilization installation 130 act collectively against water currents, which they effectively slow down. The projecting portions 105 in the stabilization installation 130 provide mutual protection of the stabilization elements 101 in the installation 130 against waves, in a manner comparable to the mutual protection that trees in a forest provide against winds. projection 105 in the stabilization installation 130 provide mutual protection of the stabilization elements 101 in the installation 130 against water currents, in a manner comparable to the mutual protection that trees in a forest provide against winds.

[0045] The projecting portions 105 in the stabilization facility 130 form a kind of reef in which marine fauna can develop. For example, in the stabilization facility 130, marine fauna can wander freely between the central empty spaces 120.

[0046] According to a first example of use, the stabilization installation 130 covers and stabilizes a sandy bottom. According to a second example of use, the stabilization installation 130 covers and stabilizes a beach or other coastal area. According to a third example of use, the stabilization installation 130 covers and stabilizes the toe of a shell of a dike.

[0047] According to other examples of use, the stabilization installation 130 is installed in fresh water, for example at the banks of a river or stream. Presentation of the invention

[0048] The invention has at least the aim of enabling progress in the fight against coastal erosion, the effects of swell and other phenomena likely to act on, alter and / or modify seabeds and / or installations which are at least partially submerged permanently or at times, for example due to tides.

[0049] According to the invention, this aim is achieved by means of an element for stabilizing a plot that is at least partially underwater at least at times, which comprises a base comprising several arms angularly offset from each other around a central axis, each arm comprising a proximal part and an end which extends this proximal part, notches in the base being located between the arms and having a shape generally complementary to the ends of the arms.

[0050] By joining several copies of the stabilizing element according to the invention, it is possible to constitute a protective layer covering a plot to be stabilized. In this protective layer, two side-by-side copies of the stabilizing element may not be exactly at the same height and / or may not have the same inclination relative to the horizontal, depending on the topography of the plot to be stabilized, that is to say depending on possible spatial variations in relief at the level of this plot. The protective layer comprising stabilizing elements according to the invention is thus adaptable to possible spatial variations in relief in the plot to be stabilized. As if it were formed of scales articulated to each other, this protective layer is also adaptable to possible changes over time in the relief in the plot to be stabilized, compared to a screed of concrete under which a hollow can form and expand over time.

[0051] Compared to conventional rockfill and known geosynthetic tubes, the invention allows a different arrangement and an equally different mode of action. The known rockfill and geosynthetic tube solutions are effective and / or possible in certain specific areas of use such as the reinforcement of dikes or the construction of breakwaters. The inventors of the present invention have found that it is possible to combat coastal erosion, the effects of swell and other phenomena capable of acting on, altering and / or modifying seabeds and / or installations that are at least partially submerged permanently or at times, for example due to tides, in a different and / or different way.

[0052] Due to the generally complementary notches at the end of each arm, two adjacent stabilizing elements according to the invention can be partially fitted into one another.

[0053] According to an advantageous possibility, the stabilizing element comprises a central portion to which the arms are connected.

[0054] According to an advantageous possibility, the central portion comprises a projecting portion which projects upwards, relative to the arms.

[0055] A grouping of such upwardly projecting projecting portions effectively breaks waves and / or effectively slows currents in water. It can act in the manner of a reef, for example a coral reef, and promote the development of fauna and flora, and the establishment of certain aquatic life, in particular marine life, including for example sedentary algae, shellfish, crustaceans, starfish, sea anemones, fish, etc. Underwater dikes made of geosynthetic tubes of the prior art or quarried stone blocks act little or practically not in the manner of a reef promoting the development and establishment of certain aquatic life, in particular marine life.

[0056] According to an advantageous possibility, the base comprises at least part of the central portion.

[0057] Thus, the base can cover a large area of ​​the plot to be stabilized.

[0058] According to an advantageous possibility, the stabilizing element comprises a central empty space surrounded by the central portion.

[0059] Thus, the stabilizing element can be lightened, which is advantageous for its transport and / or handling. In addition, less raw material can be used for its manufacture.

[0060] According to an advantageous possibility, the projecting portion comprises lateral conduits connecting the central empty space with the exterior.

[0061] Thus, aquatic fauna can use such lateral conduits to enter the central empty space used as a refuge and / or to exit it.

[0062] According to an advantageous possibility, the central empty space opens upwards, into the top of the central portion.

[0063] Thus, daylight can illuminate the central empty space used by aquatic fauna as a refuge.

[0064] According to an advantageous possibility, the central empty space opens downwards, into the underside of the base.

[0065] According to an advantageous possibility, the central empty space is a rising passage which is traversing by opening upwards, in the top of the central portion, and by opening downwards, in the bottom of the base.

[0066] Thus, when the stabilizing element is lowered or descends under its own weight into water, water may pass into the central void space, rather than braking and / or tipping the stabilizing element. In addition, daylight may illuminate the central void space used by marine wildlife as a refuge.

[0067] According to an advantageous possibility, the rising passage has a lower end, a portion higher than the center of gravity of the stabilizing element and a passage section larger at its lower end than at its portion higher than the center of gravity of the stabilizing element.

[0068] Thus, when the stabilizing element 1 is lowered or descends under the effect of its own weight into water, water is caused to rush into the central empty space, through the lower end thereof, and to form a current passing through the stabilizing element, which tends to oppose a significant tilting or even a turning over of the stabilizing element.

[0069] According to an advantageous possibility, the end of each of the arms comprises an edge having two sides which form between them a salient angle pointing in the direction opposite to the central portion.

[0070] Thus, the end has an edge capable of guiding its fitting into a complementary notch.

[0071] According to an advantageous possibility, the arms are five in number.

[0072] Thus, several copies of the stabilizing element can be arranged relative to each other on an underwater bed or another surface, in a regular and optimal manner.

[0073] Thus, several copies of the stabilizing element can be arranged relative to each other in a regular and optimal manner, leaving little exposed surface between them, for example on a seabed or another submerged surface subject to erosion.

[0074] According to an advantageous possibility, the arms are distributed regularly around the central axis.

[0075] According to an advantageous possibility, the stabilizing element comprises a relief anchoring to a ground, this anchoring relief equipping the underside of the base.

[0076] Thus, the stabilizing element remains better in its place once installed.

[0077] According to an advantageous possibility, the anchoring relief comprises pyramids in downward projection.

[0078] According to an advantageous possibility, the stabilizing element comprises a molded part which comprises or defines the arms. According to a first example, this molded part is made of molded concrete. According to a second example, the molded part is a polymer shell. According to an advantageous possibility, the stabilizing element is made of at least one material, which is concrete or a similar material.

[0079] The invention also relates to an installation for stabilizing a plot that is at least partially underwater at least at times, which comprises several stabilizing elements as defined above, the bases of the first and second stabilizing elements side by side among the stabilizing elements resting on the underwater plot, one end of one of the arms of the first stabilizing element being generally fitted into one of the notches of the second stabilizing element.

Claims

Claims

1. Element for stabilizing a plot that is at least partially underwater at least at times, characterized in that it comprises a base (102) comprising several arms (103) angularly offset from each other around a central axis (X), each arm (103) comprising a proximal part (110) and an end (111) which extends this proximal part (110), notches (115) in the base (102) located between the arms (103) and having a shape generally complementary to the ends (111) of the arms (103).

2. A stabilizing element according to claim 1, which comprises a central portion (104) to which the arms (103) connect.

3. A stabilizing element according to claim 2, wherein the central portion (104) comprises a projecting portion (105) which projects upwardly, relative to the arms (103).

4. A stabilizing element according to one of claims 2 and 3, which comprises a central empty space (120) surrounded by the central portion (104).

5. Stabilizing element according to claims 3 and 4, in which the projecting portion (105) comprises lateral conduits (125) putting the central empty space (120) into communication with the exterior.

6. Stabilizing element according to one of claims 3 to 5, in which the central empty space (120) is a rising passage which is traversing by opening upwards, in the top of the central portion (104), and by opening downwards, in the bottom (118) of the base (102).

7. A stabilizing element according to claim 6, wherein the rising passage has a lower end, a portion higher than the center of gravity (G) of the stabilizing element and a larger passage section at its lower end than at its portion higher than the center of gravity (G) of the stabilizing element.

8. A stabilizing element according to one of claims 2 to 7, wherein the tip (111) of each of the arms (103) comprises an edge (112) having two sides (113) which form between them a projecting angle pointing in the direction opposite to the central portion (104).

9. Stabilizing element according to one of claims 1 to 8, in which the arms (103) are five in number.

10. Stabilizing element according to one of claims 1 to 9, which comprises a relief (119) for anchoring to a ground, this anchoring relief (119) equipping the underside of the base (102).

11. Installation for stabilizing a plot that is at least partially underwater at least at times, characterized in that it comprises several stabilizing elements (101) according to one of claims 1 to 9, the bases (102) of the first and second stabilizing elements (101) side by side among the stabilizing elements (101) resting on the underwater plot, one end (111) of one of the arms (103) of the first stabilizing element (101) being generally fitted into one of the notches (115) of the second stabilizing element (101).

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