WO2020229253A1

WO2020229253A1 - Geotube for coastal protection barrier and coastal protection barrier comprising the geotube

Info

Publication number: WO2020229253A1
Application number: PCT/EP2020/062541
Authority: WO
Inventors: Donato Zangani
Original assignee: Rina Consulting S.p.A.
Priority date: 2019-05-13
Filing date: 2020-05-06
Publication date: 2020-11-19
Also published as: EP3969667B1; EP3969667A1; EP3969667C0

Abstract

A tubular modular structure (geotube) for coastal protection, wherein the geotube is provided by means of a sheet provided with opposite longitudinal edges (32, 33) provided at least partly with releasable coupling teeth designed to cooperate with each other in order to provide a mechanical coupling between the longitudinal edges (32, 33).

Description

GEOTUBE FOR COASTAL PROTECTION BARRIER AND COASTAL PROTECTION BARRIER COMPRISING THE GEOTUBE

The present invention relates to a geotube for a coastal protection barrier and to a coastal protection barrier comprising the geotube, in particular for protecting coasts from seashore erosion phenomena by the marine environment.

The term "barrier" is meant to indicate the solutions as a whole that use both coast protection barriers and reinforcements of existing coastal structures (comprising dune reinforcement).

As is known, the phenomenon of the erosion of coasts and seashores is per se linked to several factors (e.g. weather- and climate-related, geologic, biological and anthropic factors); however, a particularly important mechanism in the phenomenon of erosion is wave motion, which in the presence of particularly adverse climate situations leads to coastal storms characterized by high impacts on coastal structures.

In order to prevent or at least limit or mitigate this mechanism, various solutions have arisen over time which substantially have in common the fact that they generate a mechanical protection against the action of the waves.

Solutions such as breakwaters and barriers, typically made of rock and cement blocks, have thus become widespread over time.

Although they are generally functional, these solutions however have some limitations, linked to the fact that they have a significant environmental impact, since they are often fixed installations and/or require the use of raw materials (natural rocks) the availability of which in some regions is limited.

In order to solve these problems, solutions have become widespread which entail providing (instead of cement or rock barriers) barriers which provide dunes that are reinforced by means of geotubes that are usually covered with sand or soil. For this purpose, geotubes are shaped like a bag (which is indeed tubular) which is then filled with loose material (e.g., sand, soil or gravel), thus providing the barrier. In some solutions the barrier is installed so as to be partially or fully submerged and anchored to the seabed, so as to mitigate the effect of wave motion, modifying it.

These solutions that use a geotube to provide the barrier are interesting, since they are of relatively low cost, and can also be provided in an environmentally compatible manner by being integrated in the coastal landscape.

In greater detail, these barriers, used as coastal coverings for stabilizing the coastline and for protecting the coasts, absorb the energy of the waves that crash against the coast by means of a combination of energy dissipation inside the structure and of the passage of the wave motion over the surface of the structure. Sometimes these solutions are used for similar purposes, such as limiting the overlap of waves (in the condition in which the barrier is immersed or partially immersed).

One particularly interesting aspect of barriers that comprise geotubes is that these geotubes can be hidden from view, thus reducing their environmental impact.

For example, when natural dunes do not exist or when they do not provide sufficient coastal protection, barriers with a geotube provided in such a manner that the geotube is fully covered (and therefore hidden) by sand or soil or rubble provide true artificial dunes that protect the coast without affecting its appearance negatively and without modifying the ecosystem.

Furthermore, even if an erosion of the covering of the geotube occurred, the latter (although exposed) would still perform its protection function, preventing the occurrence of further damage to the coastal structures located behind it and limiting coastal erosion.

If one wishes to list the advantages of various barriers comprising geotubes, they comprise the fact that geotubes can be filled with soil or sand or, more generally, locally available loose material, can be positioned with relative precision, have a relatively rapid filling, are highly competitive in terms of costs (due to lower requirements in terms of yard machines for the handling of large volumes of material). In the prior art, geotubes are available in a variety of shapes and dimensions; the most common type for coastal barrier applications has a closed tubular shape with a circular transverse cross-section which, once installed, has a flattened configuration due to the weight of the filling material, with a diameter comprised between 1.5 and 2.5 meters; in other words, the geotubes usually used are essentially provided as cylindrical bags which are elongated in a longitudinal direction.

The enclosure of the geotube is generally prefabricated and then sent to the yard, where it is filled by pumping a mixture (normally sand-water) into the geotube and thus allowing the water to flow out through the porosity of the geotube or by means of adapted outlets for the water (which trap the sand inside the geotube but allow the water to flow out).

Known geotubes for these barrier applications are provided starting from sheets which are sewn onto themselves; the sheets are in turn provided by means of a fabric (often termed "geotextile fabric") or by means of membranes (often termed "geomembranes") or by means of a combination of the two.

Geotextile fabrics are fabrics constituted by weft and warp fibers made of synthetic material, more rarely natural material. The fabrics are therefore generally permeable to water.

Vice versa, geomembranes are generally constituted by spread fabrics or by sheets made of synthetic material which are impermeable to water.

Although in general the barriers with geotubes described above are advantageous with respect to solutions that provide for the use of massive barriers made of blocks of stone or concrete, they have some limitations that hinder a wider diffusion thereof. One of the limitations is linked to the presence of stitched seams of the sheet, which are necessary in order to obtain the desired tubular shape: the stitched seams are generally obtained by sewing the edges of the sheet onto themselves and (where necessary and where allowed by the material) by resorting to thermal bondings, if a hermetic structure is required (for example when the plasma is installed fully or partially submerged). It is therefore necessary that the material that constitutes the geotube and the stitched and/or thermally bonded junctions must be tough enough to withstand the pressure and the stresses during filling and installation.

Furthermore, this aspect entails limitations linked to the fact that due to the stitched seams a reduction in strength occurs at the joints in addition to negative effects on the overall strength of the barrier, with a consequent waste of material, since the maximum allowable strength of the geotube thus provided is equal to the maximum strength of the stitched seam and not of the sheet.

If the stitched seams are provided on site, during installation of the container, they are performed on a portable sewing machine, the stitches of which however are not optimum from the point of view of strength.

As an alternative, in order to have a greater strength, the stitched seams must be factory manufactured, and the already sewn geotube must be then transported to the installation site. This allows to improve the strength characteristics of the geotube but greatly limits versatility, since once it is provided at the factory the geotube is difficult to re-adapt to specific requirements that become evident during installation (unless cuts and stitched seams are provided again on-site, with a consequent increase in times/costs).

The two requirements, i.e., the strength of the geotube and its versatility (in the sense of adaptability to the installation requirements) are in fact opposite: in order to meet the former, it would in fact be appropriate to provide the geotube in a factory, to transport it in an already built condition and fill it on site with sand (or other), whereas to meet the latter it would be necessary to transport to the site simple sheets which are then stitched during installation to form the actual geotube that will then be filled.

The aim of the present invention is to provide a geotube for a coastal protection barrier and a coastal protection barrier comprising said geotube that is capable of improving the background in one or more of the aspects indicated above.

Within this aim, an object of the invention is to provide a geotube for a coastal protection barrier and a coastal protection barrier comprising said geotube that are at the same time tough and versatile.

Another object of the present invention is to overcome the drawbacks of the background part in a manner that is alternative to any existing solutions.

Another object of the invention is to provide a geotube for a coastal protection barrier and a coastal protection barrier comprising said geotube that are highly reliable, relatively easy to provide and at competitive costs.

This aim, as well as these and other objects which will become better apparent hereinafter, are achieved by a geotube for a coastal protection barrier according to claim 1, optionally provided with one or more of the characteristics of the dependent claims, which are understood to be an integral part of the present description.

The above aim and objects are also achieved by a coastal protection barrier comprising the geotube according to the corresponding accompanying claims, which also are to be understood as an integral part of the present description.

Further characteristics and advantages of the invention will become better apparent from the description of a preferred but not exclusive embodiment of the coastal protection device according to the invention, illustrated by way of nonlimiting example in the accompanying drawings, wherein:

Figure 1 is a perspective view of a geotube according to the invention;

Figures 2-4 are perspective views of three moments of the assembly of a tubular module of a geotube according to the invention;

Figures 5 and 6 are perspective views of two different embodiments of an end closure element of a geotube according to the invention;

Figure 7 is an exploded perspective view of a sheet of a geotube according to the invention;

Figure 8 is a sectional view of part of a sheet of a geotube according to the invention;

Figure 9 is a perspective view of a geotube with loading/discharge ports according to the invention;

Figure 10 is a sectional view of a loading port of the preceding figure; Figure 11 is a sectional view of a portion of the geotube of the invention provided with a closure patch;

Figure 12 is a perspective view of an example of a barrier device for coastal protection, installed.

With reference to the figures, the geotube for a coastal protection barrier is designated generally by the reference numeral 2, while the coastal protection barrier (an example of which is shown in Figure 12) comprising said geotube is designated generally by the reference numeral 1.

With reference to Figure 1, in its general features, the geotube 2 comprises a tubular container body 20 which is longitudinally extended and two closed ends 21 which close at the opposite terminal ends the tubular container body 20.

The geotube 2 thus delimits an internal volume; the geotube 2 is configured to be filled with a loose material accommodated in the internal volume. According to the invention, the tubular container body 20 of the geotube 2 is provided at least by one first tubular module 3 that is shaped like a tube; the embodiment of Figure 1 shows a preferred and non-limiting solution in which the tubular container body 20 of the geotube 2 is provided by means of two adjacent and coupled tubular modules 3, 30; it is pointed out right now that the tubular body 20 might be provided by means of one, two, three or more mutually connected tubular modules.

At least one, preferably all the tubular modules 3, 30 (if there is more than one) are provided by means of a (folded) sheet 31 provided at least with two opposite longitudinal edges 32, 33 which are mutually coupled so as to form the tubular shape of the module 3, 30.

According to the invention, advantageously, the opposite longitudinal edges 32, 33 of the sheet 31 are provided at least partly (i.e., at least for a portion of the total length of the edge) with releasable coupling teeth designed to mutually cooperate in order to provide a mechanical coupling between said longitudinal edges 32, 33.

As mentioned, the internal volume defined by the container body 20 of the geotube 2 is hollow and adapted to be filled with a loose material such as gravel or sand, conveyed into the volume of the container body preferably by means of a fluid which carries the loose material. According to a preferred embodiment, the fluid is a liquid, preferably water (for example seawater, which is readily available on site) with which the loose (solid) material, for example sand, rubble, gravel or the like, is mixed.

Going back now to the tubular module, with reference to the tubular module 3, it is shown in various steps of its assembly in Figures 2-4.

If there are other tubular modules 30, they are preferably identical (except optionally for the length in a longitudinal direction) to the tubular module 3; therefore, reference shall be made hereinafter only to the latter.

Figures 2-4 clearly show that the tubular module 3 is shaped like a tube starting from a sheet 31 (Figure 2) which is folded onto itself (Figure 3) and the longitudinal edges 32, 33 of which are then mutually coupled (Figure 4), thus providing the tubular shape of the module 3.

The material of the sheet 31 is described hereinafter with reference to Figures 7 and 8; for the time being suffice it to note that this material must be at least suitable for the use for which it is intended (i.e., it must allow at least filling by means of induced material carried by a fluid and must allow the geotube to be installed).

As mentioned, advantageously, according to the invention, the longitudinal edges 32, 33 of the sheet 31 are each provided with releasable coupling teeth which are configured to cooperate with each other so as to provide a mechanical coupling between said longitudinal edges 32, 33.

In this manner, the tubular shape of the module 3 can be easily provided on-site and maintained over time.

This operation is in fact extremely quick and can be performed easily on site during the installation of the device 1.

In the preferred case, shown in Figure 1, in which the tubular body 20 of the geotube 2 is provided by means of the joining of two (or more) tubular modules 3, 30, at least the transverse edge of one module 3 is coupled to the transverse edge of a further adjacent module 30.

The geotube 2 is then finalized by means of the provision (application) of the closed ends 21.

Such ends preferably comprise an end closure device which is shown in two embodiments 8, 80 in Figures 5 and 6.

In order to allow easy coupling between adjacent tubular modules 3, 30 and/or the application of the end closure devices 8, 80 at the closed ends 21, the transverse opposite edges 34, 35 of the sheet 31 also are provided at least partly (i.e., at least for a portion of the total length of the edge) with releasable coupling teeth, which are identical or similar to those of the longitudinal edges.

In this manner it is possible to create geotubes 2 having any length simply by mutually joining a preferred number of tubular modules 3, 30 and then applying the end closure devices 8, 80 at the closed ends 21.

This allows to have available not only a solution that is versatile but also a tough one, since it is not necessary to perform stitching and/or thermal bonding operations on site.

Furthermore, the presence of the transverse couplings on the edges 34, 35 of two nearby modules strengthens the structure as a whole, due to the rib-like function that these coupling teeth perform on the transverse edges of each module 3, 30.

According to one variation, instead of the end closure devices 8, 80 connected by means of the teeth to the tubular body 20, there are two terminal modules (not shown), each provided with a stably closed end, which thus provides one of the two opposite closed ends 21.

For example, the end modules might have a terminal end which is sewn and/or glued onto itself; during installation, the various tubular modules 3, 30 are mutually coupled in the manner described above, taking care to couple, at the end of the line of tubular modules 3, 30, one terminal module for each end.

According to this variation, the geotube might also be provided just by joining two end modules to each other.

Although this solution is apparently simple, it forces however to have available various types of modules, i.e., both those of the type 3, 30 (open at the ends) and the terminal ones (which have a closed end).

As regards instead the end closure elements of Figures 5 and 6, they are preferably made of the same material as the sheet 31 and have for example a dome-like shape 9 (Figure 5) or a substantially pyramid-like shape 90 (Figure 6); in one variation, not shown, the end closure element that provides the closed end 21 of the geotube 2 is provided as a simple planar partition.

In all cases, if provided, the end closure elements comprise releasable coupling teeth 85 which can be coupled (therefore of the same type and number) with the releasable coupling teeth of a transverse edge 35 of a tubular module 3.

The material of the sheet 31 is now described and reference should be made to Figures 7 and 8.

Preferably, the sheet 31 is a sheet that is permeable to liquids, for example permeable to water.

Preferably, the sheet 31 is a multilayer sheet and comprises a sandwich-like structure, in which multiple layers 31 A, 3 IB, 31C are mutually superimposed and rendered integral.

In the preferred and non-limiting embodiment of Figures 7 and 8 there is an upper layer 31 A and a lower layer 31C with a reinforcement function, between which an intermediate layer 3 IB is located.

Preferably, the upper layer 31 A and the lower layer 31C are made of natural fiber, preferably coconut, which is mesh woven.

More preferably, the mesh woven natural fiber, preferably made of coconut, has square mesh units, with a center distance between the fibers on the order of 2-3 cm, a minimum degree of coverage of 70%, a thickness of approximately 5 mm and a minimum nominal mass per unit area approximately equal to 500 g/m²; the minimum tensile strength is approximately equal to 10 kN/m.

The intermediate layer 3B has the function of a filter in order to prevent the particles of loose material (e.g. sand) from exiting from the geotube 2; it is preferably constituted at least by a nonwoven isotropic mat made of natural fiber, preferably made of coconut, with a chaotic structure.

Preferably, the mat is provided by means of a random weave of natural fibers, preferably of coconut, with a minimum nominal mass per unit area approximately equal to 250 g/m² and a thickness of approximately 5 mm.

The three layers 31 A, 31B, 31C are rendered integral by sewing with a thread 3 ID which engages in a random manner the natural fibers of the three layers 31 A, 3 IB, 31C.

The stitching with thread 3 ID, shown in Figure 8, does not have a structural function but has the function of rendering integral the layers for better ease in handling and working in the yard.

Optionally it is possible to provide additional external and intermediate layers, not shown.

As an alternative to coconut fiber, it is possible to use as natural fibers other fibers, for example fibers of jute, hemp or the like.

Furthermore, it is possible to apply optionally to the sheet 31 surface treatments which are not described here in detail.

As regards the filling of the device 1 with the loose material, and with reference now to Figures 9 and 10, the geotube 2 comprises preferably a loading port 9 which is configured at least to connect at least the internal volume of the tubular body 20 to a source of filling fluid and to close selectively the access to the internal volume of the tubular body 20, so as to prevent the loose material from being able to exit from the loading port 9.

In a preferred solution, shown in Figure 9, the geotube 2 furthermore optionally comprises a discharge port 90 in order to allow the outflow of the loose material conveyance liquid; such port is particularly useful when the sheet 31 is provided so that it is not permeable to water.

Preferably, the loading port 9 is applied to the tubular body 20, while the discharge port 90, if present, is applied to a closed end 21.

Preferably, the loading port 9 is arranged at a portion of the tubular body 20 that is directed upward when installed, whereas the discharge port 90, if present, is applied to a portion of the tubular body 20 that is directed downward so as to facilitate the loading/discharge steps.

With reference now to Figure 10, the loading port 9, in a preferred and non-limiting embodiment, comprises an external flange portion which has a coupling duct 91 joined to a wider flange base 92 and an internal flange portion 93 which mates with the external one 91 by virtue of coupling elements 94 (for example of the screw type, such as bolts and nuts).

The sheet 31 has, at the port 9, an opening 37, by means of which access to the internal volume of the tubular body 2 is ensured at least for the loading of the loose material conveyed by the liquid.

The external flange portion and the internal flange portion are mounted so that the flaps of the sheet 31 are interposed between the two, so that the tightening of the coupling elements makes the assembly stable; optionally it is possible to provide sealing elements 99 which are adjacent to the flaps of the sheet, between the latter and the flanges 92, 93.

In a preferred solution, the loading port 9 is removable, so that once the filling of the geotube 2 has ended it can be removed and replaced with a less expensive closure patch 97, such as the one shown in Figure 11.

For this purpose, if the loading port 9 is provided as in the preferred embodiment of Figure 10, it is sufficient to remove manually the coupling elements 94 and then remove both flange portions (internal and external); then a closure patch 97 is inserted instead of the internal flange, at the opening 37 of the sheet 31, and is optionally fixed thereat in position with coupling means 98 (for example brackets).

Optionally, especially if the loading port 9 has to be left in position on the geotube even after installation, it comprises a closure flap (or wing) which can be moved to open or close the aperture of the port and prevent the outflow of the loose material contained in the geotube 2.

As regards the opening 37 at which the port 9 is fitted, it can be a hole provided for this purpose in the sheet 31 but it is preferable that the opening 37 be the one that forms between the longitudinal edges 32, 33 and/or transverse edges of the sheet, so as to not have to perforate the sheet itself.

Even more preferably, in the preferred embodiment shown in Figure 9, if the tubular body 20 is formed by a plurality of tubular modules 3, 30, the port 9 is arranged so as to coincide with the meeting point of the coupled transverse edges of the modules 3, 30 and of the coupled longitudinal edges 32, 33 of both tubular modules 3, 30. In this manner, the port 9 is in the connecting point of a plurality of modules and allows to discharge any forces (applied thereto in the filling of the tubular body) also onto the releasable coupling teeth of the connecting regions that are adjacent to the port 9.

The releasable coupling teeth of the longitudinal and/or transverse edges of the sheet 31 are shaped like the teeth of a zip fastener or zipper.

The teeth are provided on the respective edge of the sheet 31, being coupled directly thereto or, in an equivalent manner, being coupled to a supporting tape which is then in turn coupled to the respective edge of the sheet 31.

Preferably, the releasable coupling teeth are configured to provide a liquid-tight coupling.

Even more preferably, there is at least one closing/opening slider element adapted to move the releasable coupling teeth of a releasable coupling to a coupled or uncoupled condition, providing in practice a true zip fastener or zipper.

In greater detail, in a preferred solution, the preferential zip fastener configuration that can be used is the one described in US 005/678285A entitled "Zipper for heavy loads", whose characteristics of high strength and use in aggressive environments are well suited to the present application.

The teeth of the zip fastener might be made of different materials, preferably of plastic material and injection-molded onto the supporting tape.

The plastic material preferably has recyclability characteristics or is obtained from natural sources (for example polylactic acid, PLA) or mixtures thereof.

The tape of the zip fastener is provided starting from textile fibers, preferably from natural fibers or from recycled synthetic fibers or from combinations thereof in the weft and warp.

If a hermetic sealing effect is desired, the configuration of the zip fastener can be advantageously the one described in WO 2010/040471 A1 ("Watertight zip fastener with barrier effect").

The assembly and use of the geotube 2 according to the invention is as follows.

The operators transport to the site the sheets 31 and provide with them a number of tubular modules 3, 30 that is sufficient for the installation simply by appropriately coupling the longitudinal edges 32, 33, 320, 330 of each sheet 31.

Once this operation has ended, the operators mutually connect or couple the tubular modules 3, 30 thus provided, aligning them and coupling a module 3 to one or two adjacent tubular modules (depending on whether the module being considered is at the end of the series or not), coupling them by means of the teeth provided on the transverse edges thereof, thus providing the tubular container 20.

If necessary, one or more ports 9 and/or 90 are fitted in this step.

At the end of this operation, the operators close the tubular container 20 at the ends 21, for example by means of the end elements 8, 80.

The geotube 2, which is still empty internally, is then oriented or folded until it assumes the desired shape (for example, an arc-like shape or the like).

The operators then connect a source of filling fluid, for example comprising a pump which draws seawater and a mixer that mixes it with sand or other loose material.

The filling fluid is then pumped into the body by means of the port 9.

The water exits by passing through the permeable sheet 31 or through the discharge port 90 (if the sheet is not permeable) while the sand (or loose material) remains trapped inside the geotube 2, progressively filling it. Figure 12 instead shows a coastal protection barrier 1 which comprises a plurality of geotubes 2 of the type that has just been described and has been installed.

In this example, the barrier 1 comprises three geotubes 2 of the type just described, which are covered by means of a layer of earth or sand 11 until they remain hidden from view and form a hill or dune that has a natural appearance and is capable of limiting coastal erosion.

In practice it has been found that the invention achieves the intended aim and objects, providing a device which is at the same time tough and versatile, relatively low in cost and easy to install.

In greater detail, the advantages can be presented schematically as follows:

- modularity: it is possible to build a geotube of the desired length by coupling together multiple tubular modules;

- process automation and control: a higher level of automation and quality control of the final product is achieved, since the need to provide stitched seams or joints on site is avoided completely;

- greater strength of the coupling points: the use of zip fasteners the strength of which can be adapted according to the design requirements of the application;

- higher productivity: by virtue of the reduction of the manual operations on site and the flexibility of the zip fastener;

- lower maintenance: in case of damage of a module of a geotube, it can be simply replaced with a new one;

- very low environmental impact: the proposed solution can be constituted almost entirely of means of natural fibers (coconut, jute, hemp, or others) differently from currently commercially available geotubes constituted of synthetic fibers and plastic materials; in case of rupture of the geotubes or big bags that are currently commercially available and are used for coastal protection, the result is the scattering into the environment of plastic sheets, with severe environmental impacts. Vice versa, in the case of natural materials the environmental impact is very low and furthermore the modularity of the system would allow to repair the damaged portion and to rapidly restore the structure;

- facilitated reversibility of the structure: when it is no longer useful and must be removed, its disassembly is rendered simple by the opening of the zip fasteners, which allows its easy emptying and consequent removal.

The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims; all the details may furthermore be replaced with other technically equivalent elements.

In practice, the materials used (so long as they are compatible with the specific use), as well as the contingent shapes and dimensions, may be any according to the requirements and the state of the art.

The disclosures in Italian Patent Application No. 102019000006748 from which this application claims priority are incorporated herein by reference.

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

1. A geotube (2) for a coastal protection barrier (1) comprising a tubular container body (20) which is longitudinally extended and two terminal ends (21) for the closure of the tubular body (20), the geotube (2) delimiting a volume that is internal at least to the tubular body (20) and being configured to be filled with a loose material,

the tubular body (20) of the geotube (2) comprising at least one first tubular module (3) that is shaped like a tube and is provided by means of a sheet (31) provided at least with two opposite longitudinal edges (32, 33) which are mutually coupled so as to form said tube

characterized in that

said opposite longitudinal edges (32, 33) of said sheet (31) are provided at least partly with releasable coupling teeth designed to cooperate with each other in order to provide a mechanical coupling between said longitudinal edges (32, 33).

2. The geotube (2) according to claim 1, characterized in that said sheet (31) comprises two opposite transverse edges (34, 35) provided at least partly with releasable coupling teeth, so as to allow the coupling of said transverse edges (34, 35) with an adjacent additional tubular module (30) or with an end closure device (8, 80).

3. The geotube (2) according to claim 1 or 2, characterized in that it comprises a plurality of substantially aligned tubular modules (3, 30), in which two mutually adjacent tubular modules (3, 30) are coupled to each other at least by means of the releasable coupling teeth of a transverse edge (34) of a module which are engaged with the releasable coupling teeth of a transverse edge (35) of the adjacent module (30).

4. The geotube (2) according to one or more of the preceding claims, characterized in that each one of the closed terminal ends (21) of the geotube (2) comprises an end closure element (8, 80), each end closure element being provided with releasable coupling teeth which can be coupled to the releasable coupling teeth of a transverse edge of a tubular module (3, 30).

5. The geotube (2) according to one or more of the preceding claims, characterized in that it comprises closing/opening slider elements configured to move the releasable coupling teeth of a releasable coupling to the coupled or uncoupled condition.

6. The geotube (2) according to one or more of the preceding claims, characterized in that it comprises a loading port (9) configured at least to connect an internal volume of the geotube (2) to a source of filling fluid.

7. The geotube (2) according to one or more of the preceding claims, characterized in that said loading port (9) is arranged so as to coincide with longitudinal edges (32, 33) and/or transverse edges of the sheet (31).

8. The geotube (2) according to one or more of the preceding claims, characterized in that said sheet (31) is a sheet that is permeable to liquids and preferably permeable to water.

9. The geotube (2) according to one or more of the preceding claims, characterized in that said sheet (31) is a multilayer sheet and comprises a sandwich-like structure in which multiple layers (31 A, 3 IB, 31C) are mutually superimposed and rendered integral, comprising an upper layer (31 A) and a lower layer (31C) with a reinforcement function, between which an intermediate layer (3 IB) with a filtering function is located.

10. The geotube (2) according to the preceding claim, characterized in that the upper layer (31 A) and the lower layer (31C) are made of natural fiber, preferably coconut fiber, mesh woven, in which preferably the mesh has square mesh units, with a center distance between the fibers on the order of 2-3 cm, a minimum degree of coverage of 70%, a thickness of approximately 5 mm and a minimum nominal mass per unit area approximately equal to 500 g/m²; the minimum tensile strength is approximately equal to 10 kN/m.

11. The geotube (2) according to claim 10, characterized in that the intermediate layer (3B) comprises a nonwoven isotropic mat made of natural fiber, preferably coconut, with a chaotic structure, preferably provided by means of a random weaving of natural fibers, preferably coconut fibers, with a minimum nominal mass per unit area approximately equal to 250 g/m² and a thickness of approximately 5 mm.

12. The geotube (2) according to one or more of claims 9 to 11, characterized in that the layers (31 A, 3 IB, 31C) are rendered integral by stitching with thread (3 ID) which randomly engages the natural fibers of the layers (31 A, 3 IB, 31C).

13. A coastal protection barrier (1) comprising a geotube (2) according to one or more of the preceding claims.