Element and installation for stabilizing an underwater plot

Description

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, alter and / or modify seabeds and / or installations at least partially submerged permanently or at times, for example due to tides.

[0002] More specifically, the invention relates to a stabilization element for a plot of land that is at least partially underwater at least at times, as well as an installation comprising several examples of this stabilization element. Document WO 2019 / 180359 A1 discloses a stabilization element.

[0003] For example, the invention can be applied to the stabilization of a coastal beach, the stabilization of a seabed such as a sandy bottom, the stabilization of a cliff base and / or the stabilization of a dike armor base. STATE OF THE ART

[0004] Underwater breakwaters made of quarried stone blocks or geosynthetic tube systems, which are elongated bags filled with sand, have been proposed. Geosynthetic tubes are not a sustainable and therefore unsatisfactory solution, as they are highly vulnerable to navigational incidents such as impacts from ships, anchors, and various floating objects.

[0005] The warming of Earth's atmosphere is becoming increasingly a reality, with multiple consequences including rising sea and ocean levels, as well as an increase in the frequency and intensity of storms.

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

[0007] Therefore, an old need remains relevant. This is the need to make progress in the fight against coastal erosion, the retreat of the shoreline, the effects of swell and other phenomena likely to act, alter and / or modify seabeds and / or installations at least partially submerged permanently or at times, for example due to tides. SUMMARY OF THE INVENTION

[0008] A section of shoreline that is alternately underwater and exposed, with the repeated cycle of high and low tide, is an example of a section that is at least partially underwater at times. The base of a seawall is another example of a section that is at least partially underwater at times.

[0009] A stabilization element for a plot of land that is at least partially underwater at times comprises a base with several arms offset angularly from each other around a central axis. The ends of each arm and notches in the base, between the arms, have generally complementary shapes, allowing adjacent stabilization elements to be partially nested within one another. DESCRIPTION OF THE INVENTION

[0010] The invention aims at least to enable progress in the fight against coastal erosion, the effects of swell and other phenomena likely to act, alter and / or modify seabeds and / or installations at least partially submerged permanently or at times, for example due to tides.

[0011] According to the invention, this goal is achieved by means of a stabilization element for a plot at least partially underwater at least at times, which comprises a base including several arms offset angularly from each other around a central axis, each arm having a proximal part and an end which extends this proximal part, notches in the base being located between the arms and having a shape that is generally complementary to the ends of the arms.

[0012] By joining several examples of the stabilizing element according to the invention, a protective layer can be created covering a plot of land to be stabilized. Within this protective layer, two adjacent examples of the stabilizing element may not be at exactly 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, depending on any spatial variations in relief within that plot. The protective layer comprising stabilizing elements according to the invention is thus adaptable to any spatial variations in relief within the plot to be stabilized.As if it were formed of scales articulated to one another, this protective layer is also adaptive to possible changes over time in the relief in the plot to be stabilized, compared to a concrete slab under which a hollow can form and enlarge over time.

[0013] Compared to conventional riprap and known geosynthetic tubes, the invention allows for a different arrangement and a different mode of action. Known riprap and geosynthetic tube solutions are effective and / or feasible in certain specific applications, such as dike reinforcement or breakwater construction. The inventors of the present invention have found that it is possible to combat coastal erosion, wave action, and other phenomena that can affect, alter, and / or modify seabeds and / or structures that are at least partially submerged, either permanently or intermittently, for example, due to tides, by alternative and / or different means.

[0014] Due to the generally complementary notches at the end of each arm, two adjacent stabilizing elements according to the invention can be partially nested one inside the other.

[0015] In some embodiments, the stabilizing element includes a central portion to which the arms connect.

[0016] In some embodiments, the central portion includes a projecting portion that projects upwards relative to the arms.

[0017] A grouping of such upward-projecting sections effectively breaks waves and / or slows currents in water. It can act like a reef, for example a coral reef, and promote the development of fauna and flora, and the establishment of certain aquatic life, particularly marine life, including, for example, resident algae, shellfish, crustaceans, starfish, sea anemones, fish, etc. Submarine breakwaters made of geosynthetic tubes from earlier construction or blocks of stone extracted from quarries have little or no effect on the reef-like structure that promotes the development and establishment of certain aquatic life, particularly marine life.

[0018] In some embodiments, the base includes at least a part of the central portion.

[0019] Thanks to these arrangements, the base can cover a significant area of ​​the plot to be stabilized.

[0020] In some embodiments, the stabilizing element includes a central empty space surrounded by the central portion.

[0021] Thanks to these provisions, the stabilizing element can be made lighter, which is advantageous for its transport and / or handling. Furthermore, less raw material can be used in its manufacture.

[0022] In some embodiments, the projecting portion includes lateral conduits connecting the central void space with the outside.

[0023] Thanks to these arrangements, aquatic fauna can use such lateral conduits to enter and / or exit the central empty space used as a refuge.

[0024] In some embodiments, the central empty space opens upwards into the top of the central portion.

[0025] Thanks to these arrangements, daylight can illuminate the central empty space used by aquatic fauna as a refuge.

[0026] In some embodiments, the central empty space opens downwards into the underside of the base.

[0027] In some embodiments, the central empty space is an ascending passage which is traversing upwards, into the top of the central portion, and downwards, into the bottom of the base.

[0028] Thanks to these features, when the stabilizing element is lowered or descends under its own weight in water, water can flow into the central void, rather than slowing it down and / or causing it to tip over. Furthermore, daylight can illuminate the central void, which marine life uses as a refuge.

[0029] In some embodiments, the rising passage has a lower end, a part higher than the center of gravity of the stabilizing element, and a larger passage section at its lower end than at its part higher than the center of gravity of the stabilizing element.

[0030] Thanks to these arrangements, when the stabilizing element 1 is lowered or descends under the effect of its own weight in water, water is forced into the central empty space, through its lower end, and forms a current through the stabilizing element, which tends to oppose a significant tilting or even a reversal of the stabilizing element.

[0031] In some embodiments, the end of each arm has an edge having two sides which form a salient angle pointing in the opposite direction to the central portion.

[0032] Thanks to these arrangements, the end has an edge capable of guiding its fitting into a complementary notch.

[0033] In some embodiments, there are five arms.

[0034] Thanks to these arrangements, several copies of the stabilizing element can be arranged in relation to each other on a seabed or other surface, in a regular and optimal manner.

[0035] Thanks to these arrangements, several copies of the stabilizing element can be arranged in relation to each other in a regular and optimal manner, leaving little exposed surface between them, for example on a seabed or other submerged surface subject to erosion.

[0036] In some embodiments, the arms are evenly distributed around the central axis.

[0037] In some embodiments, the stabilizing element includes a ground anchoring relief, this ground anchoring relief being fitted to the underside of the base.

[0038] Thanks to these provisions, the stabilizing element stays in place better once installed.

[0039] In some embodiments, the anchoring relief includes downward-projecting pyramids.

[0040] In some embodiments, the stabilizing element includes a molded portion that comprises or defines the arms. In one example, this molded portion is made of cast concrete. In another example, the molded portion is a polymer shell. In some embodiments, the stabilizing element is made of at least one material, which is concrete or a similar material.

[0041] The invention also relates to a stabilization installation for a plot that is at least partially underwater at least at times, which comprises several stabilization elements as defined above, the bases of the first and second stabilization elements side by side among the stabilization elements resting on the underwater plot, one end of one of the arms of the first stabilization element being globally fitted into one of the notches of the second stabilization element. BRIEF DESCRIPTION OF THE FIGURES

[0042] Other advantages and features will become clearer from the following description of a particular embodiment of the invention, given by way of non-limiting example and shown in the accompanying drawings, including: There figure 1 is a perspective view of a stabilizing element according to an embodiment of the invention, in place on a seabed, The figure 2 is a top view of the stabilizing element visible on the figure 1 , There figure 3 is a view from below of the stabilizing element visible on the figures 1 And 2 , There figure 4 is seen in axial section of the stabilizing element visible on the figures 1 à 3 , There figure 5 is a side view on which the stabilizing element is visible on the figures 1 à 4 is submerged and permanently fixed to a seabed, and The figure 6 is a schematic, top view showing a permanent underwater stabilization installation comprising a grouping of several adjoining examples of the stabilization element of figures 1 à 5 . DESCRIPTION OF IMPLEMENTATION METHODS

[0043] On the figure 1 , a stabilization element 101 according to an embodiment of the invention rests on a seabed F to be stabilized, such as a stretch of underwater sand subjected to intermittent sea currents.

[0044] A base 102 of the stabilizing element 101 comprises several arms 103 that are generally identical, which connect to a central portion 104.

[0045] When the stabilizing element 101 is in place, for example on a seabed F to be stabilized, its base 102, including the arms 103, rests on this seabed F, which is the case on the figure 1 .

[0046] In what follows and in the attached claims, the terms "bottom", "top", "below", "above" and "lateral", as well as similar terms, consider that the stabilizing element 101 is permanently installed and operational at its final destination 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 permanently installed stabilizing element 1 rests on an irregular and / or inclined surface of a plot to be stabilized.

[0047] The central portion 104 includes a projecting portion 105, which projects upwards, relative to the arms 103.

[0048] The arms 103 are arranged in a star shape and are angularly offset from each other around a central axis X.

[0049] As one can clearly see on the figures 2 et 3 , the 103 arms are radial arms, each of which extends along a radial axis R perpendicular to the central axis X.

[0050] The 103 arms are evenly distributed around the central axis X. In other words, the angle between the two 103 arms of a pair of consecutive 103 arms is generally the same, regardless of the specific pair of consecutive 103 arms. The angle α between two consecutive 103 arms of any pair of consecutive 103 arms is generally equal to 360° divided by the number n of 103 arms.

[0051] 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 globally equal to 72°.

[0052] In the embodiment shown, there are five arms 103, all of the same length. According to a first embodiment, the number n of arms 103 may be different from five. According to a second embodiment, the arms 103 have different lengths. According to a third embodiment, the number n of arms 103 is not five and the arms 103 have different lengths.

[0053] Each arm 103 has a proximal part 110 which connects to the central part 104. Each arm 103 has an end 111 which extends its proximal part 110. Each end 111 has an edge 112 having two sides 113 which form a salient angle between them pointing in the opposite direction to the central portion 104.

[0054] The base 102 has identical notches 115. Each notch 115 is located between two consecutive arms 103 that define its boundaries. Each notch 115 has a shape that is generally complementary to any end 111. Each notch 115 has an edge 116 with two sides 117 that form a re-entrant angle pointing towards the central portion 104. Each side 117 is generally the same length as each side 113.

[0055] As can be seen on the figures 3 And 4 The underside 118 of the base 102 is provided with pyramids 119 which project downwards. The pyramids 119 form an anchoring relief for the stabilizing element 1 in the seabed F.

[0056] As can be clearly seen on the figure 4 , the central portion 104 is hollow and crossed from one side to the other by a central void space 120. This central void passage 120 has the shape of an ascending passage which opens upwards, into the top of the projecting portion 105, and which opens downwards, into the bottom 118 of the base 102.

[0057] The central void space 120 is flared so that its cross-sectional area decreases as one ascends. The cross-sectional area of ​​the central void space 120 is thus larger at its lower end than at the upper part of this central void space 120 located above the center of gravity G of the stabilizing element 1. When the stabilizing element 1 is lowered or descends under its own weight into water until it reaches the area to be stabilized, water is thus forced into the central void space 120, through its lower end, and forms a current flowing through the stabilizing element 1, which tends to prevent significant tilting or even overturning of the stabilizing element 1.

[0058] The projecting portion 105 includes lateral conduits 125 connecting the central void space 120 with the space outside the stabilizing element 101.

[0059] When the stabilizing element 101, located on the seabed F, is submerged, the central void 120, filled with water, forms a refuge for marine fauna. This marine fauna can use the lateral conduits 125 to enter and exit the central void 120.

[0060] On the figure 5 , the stabilizing element 101 is in place on the seabed F. Its base 102 covers a parcel of this seabed F and thus protects this parcel 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 parcel against waves.

[0061] Stabilizing element 101 is made of concrete. This concrete is either unreinforced or reinforced, for example, with fibers such as glass fibers, carbon fibers, polymer fibers and / or with other reinforcements chosen from those that do not swell in the presence of chlorides if stabilizing element 1 is intended for a marine or oceanic environment.

[0062] According to one variant, the stabilization element 101 comprises an envelope such as a shell or lost formwork, this envelope containing molded concrete and / or one or more granular materials such as sand, gravel, stones, pebbles and / or a mixture of several of them.

[0063] Preferably, the stabilization element 101 is manufactured on or near the site of the plot it will be used to stabilize. This avoids the transport of large and heavy elements over long distances, which is not usually the case when constructing an underwater breakwater from stone blocks extracted from quarries.

[0064] On the figure 3 , a stabilization installation 130 for a larger portion of the seabed F comprises two rows of stabilization elements 101 themselves joined together, which rest on this seabed F.

[0065] In each row, it is repeated that an 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. In addition, an end 111 of each stabilizing element 101 of the row to the right on the figure 6 is fitted into a notch 115 of a stabilizing element 101 of the row on the left on the figure 6 .

[0066] 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 also blocking each other in horizontal translation.

[0067] On the figure 6 , the stabilization installation 130 only includes five stabilization elements 101 for the sake of clarity.

[0068] As can be seen on the figure 6The majority of the plot where the stabilization installation 130 is located is covered by the stabilization elements 1. There are indeed some exposed areas 140 between the stabilization elements 101. However, these exposed areas 140 are few in number and each has a small surface area. It is very difficult for a water current, or for the eddies of breaking waves, to reach them due to their small size and depth relative to the tops of the arms 103. Furthermore, depending on the nature of the subgrade, an anti-scour mat can be laid beforehand, preventing loss of subgrade soil.

[0069] Two consecutive stabilization elements 1 of the stabilization system 130 may not be at exactly 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, i.e., depending on any spatial variations in relief within that plot. The stabilization system 130 forms a protective shell that is thus adaptable to any spatial variations in relief within the plot to be stabilized. As if it were formed of scales hinged to one another, this protective shell is also adaptable to possible changes over time in the spatial variations in relief within the plot to be stabilized, unlike a concrete slab under which a hollow can form and enlarge over time.

[0070] The projecting sections 105 in the stabilization system 130 act collectively against potential waves, which they effectively break. The projecting sections 105 in the stabilization system 130 provide mutual protection to the stabilization elements 101 in the system 130 against waves, in a manner comparable to the mutual protection that trees in a forest provide against wind. The projecting sections 105 in the stabilization system 130 act collectively against water currents, which they effectively slow down. The projecting sections 105 in the stabilization system 130 provide mutual protection to the stabilization elements 101 in the system 130 against water currents, in a manner comparable to the mutual protection that trees in a forest provide against wind.

[0071] The protruding portions 105 in the stabilization unit 130 form a kind of reef in which marine fauna can develop. For example, in the stabilization unit 130, marine fauna can roam freely between the central open spaces 120.

[0072] In one example of its use, the 130 stabilization system covers and stabilizes a sandy bottom. In another example, the 130 stabilization system covers and stabilizes a beach or other coastal area. In a third example, the 130 stabilization system covers and stabilizes the base of a breakwater's armor layer.

[0073] According to other examples of use, the 130 stabilization installation is installed in fresh water, for example at the banks of a river or stream.

Claims

1. Stabilisation element for stabilising a plot at least partially underwater at least periodically, which element is characterised in that it comprises a base (102) comprising a plurality of arms (103) angularly offset from each other around a central axis (X), each arm (103) comprising a proximal portion (110) and an end (111) that prolongs this proximal portion (110), cut-outs (115) in the base (102) being located between the arms (103) and having a shape that generally complements the ends (111) of the arms (103), a central portion (104) to which the arms (103) are connected, a central empty space (120) enclosed by the central portion (104), the central empty space (120) being an upright passage which is a through-passage opening upwards, in the top of the central portion (104), and opening downwards, in the bottom (118) of the base (102), the upright passage having a lower extremity, a portion higher than the centre of gravity (G) of the stabilisation element characterised by having a passage cross-section that is wider in its lower extremity than in its portion higher than the centre of gravity (G) of the stabilisation element.

2. Stabilisation element according to claim 1, wherein the central portion (104) comprises a protruding portion (105) that projects upwards, relative to the arms (103).

3. Stabilisation element according to claim 2, wherein the protruding portion (105) comprises lateral channels (125) connecting the central empty space (120) with the exterior.

4. Stabilisation element according to one of claims 1 to 3, wherein the end (111) of each of the arms (103) comprises an edge (112) having two sides (113) that form a protruding angle to one another pointing in the direction opposite the central portion (104).

5. Stabilisation element according to one of claims 1 to 4, wherein there are five arms (103).

6. Stabilisation element according to one of claims 1 to 5, which comprises a relief (119) for anchoring to a ground, this anchoring relief (119) being fitted to the bottom of the base (102).

7. Stabilisation installation for stabilising a plot at least partially underwater at least periodically, which installation is characterised in that it comprises a plurality of stabilisation elements (101) according to one of claims 1 to 6, the bases (102) of adjacent first and second stabilisation elements (101) among the stabilisation elements (101) resting on the underwater plot, one end (111) of one of the arms (103) of the first stabilisation element (101) being generally nested within one of the cut-outs (115) of the second stabilisation element (101).

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