EP4649203A1

EP4649203A1 - Modular retaining element for soil retaining walls

Info

Publication number: EP4649203A1
Application number: EP24701726.2A
Authority: EP
Inventors: Nicola BRUSA
Original assignee: Hyper Fibers Srl
Current assignee: Hyper Fibers Srl
Priority date: 2023-01-13
Filing date: 2024-01-03
Publication date: 2025-11-19
Also published as: WO2024150079A9; WO2024150079A1

Abstract

Modular retaining element (1) for retaining walls (W) of soil (G) comprising a synthetic profile (2) developing along a main development axis (X) and having a plurality of inner chambers (C). The profile (2) comprises a support wall (3) and a side wall (4) having respective inner faces (3', 4') inclined towards each other according to an angle of inclination (α) that is lower than or equal to 90° so as to define, during a configuration of use of the element (1), a soil retaining surface (G). The supporting wall (3) has, on a lower face (3'') opposite to the respective inner face (3'), a first coupling element (5). The side wall (4) has, at a free end edge (4a) of the side wall (4), a second coupling element (6) that is counter-shaped with respect to the first coupling element (5), so as to allow for the coupling of at least two modular retaining elements (1) to form a retaining wall (W) without interruptions.

Description

MODULAR RETAINING ELEMENT FOR SOIL RETAINING WALLS

Technical Field

The present invention relates to a modular retaining element for soil retaining walls and a related kit for building a soil retaining wall.

In particular, the present invention relates to a modular retaining element and a kit for building retaining/supporting/reinforcing walls suitable for containing/supporting/reinforcing soil in situ following civil works of a geotechnical, rehabilitation, structural consolidation, hydrogeological instability and more generally for the building and construction sector.

The technique known for creating retaining walls or reinforced soil, involves the use of facing elements typically made of concrete (either segmental blocks or panels) and steel mesh (also known as formwork). The known elements are in the form of a block or panel or net or cage.

These elements are prefabricated and placed in situ in a single manner (laid one at a time) due to their weight or shape characteristics. In addition, these elements are often small in size (e.g. 80 cm high with a maximum length of 3 m for formwork; 20 cm high with a maximum length of 50 cm for blocks; 1.5 m high with a maximum length of 1.5 m for panels) precisely because they have to be laid individually, usually by several workers on site.

As far as concrete elements are concerned: the panels are made of reinforced concrete and can be produced either on site or in the factory through the use of formwork, typically with a minimum thickness of 14-18cm; they are laid using a crane or excavator so that they can be easily lifted as they are heavy; segmental blocks are produced in the factory, through specific prefabrication plants, typically with a block making machine or mould, filled with a cement mixture without reinforcement. They are laid manually or with a lifting clamp - typically, the weight of each block is more than 25 kg. Both concrete systems must be cured in order to reach the required strength properties prior to installation. They are usually laid only 28 days after production.

As for the steel net:

- electrowelded wire mesh formwork is used with 6 or 8 mm diameter wire bent to form the desired facing angle; the formwork is disposable, its function being to contain the soil in the wall. The soil reinforcement (e.g. geosynthetic) is simply placed in adherence to the formwork, or turned up onto the formwork, or connected with a bar to the formwork itself; or

- double twist mesh used as formwork or a gabion for the wall face is mentioned. Typically, the reinforcement is placed adhering below the wire mesh of the gabion element or turned up at the back.

Known systems are therefore defined by individual elements, which can be heavy and bulky, difficult to transport and install, and require long production and installation times. In addition, the cost of raw materials and labour for the construction of retaining walls can have a significant impact on the cost of the work.

Object of the invention

In this context, the technical task underlying the present invention is to propose a modular retaining element for retaining walls of soil and a kit for building a retaining wall of soil that overcome one or more of the drawbacks of the above-mentioned prior art.

In particular, it is the purpose of the present invention to provide a modular retaining element for soil retaining walls that is inexpensive, quick and easy to build, versatile and highly customisable, light and agile to handle.

A further aim of the present invention is to propose a kit for building a retaining wall of soil that is inexpensive, easy to handle and easy to install, and that allows a high-performance retaining wall to be built in a short time, improving the efficiency of the entire construction process.

The specified technical task and purposes are substantially achieved by a modular retaining element and a kit for building retaining walls of soil, comprising the technical features set out in one or more of the appended claims.

In particular, in a first aspect, the present invention provides a modular retaining element for retaining walls of soil comprising a synthetic profile developing along a main development axis and presenting a plurality of inner chambers.

Consequently, the retaining element can easily be produced quickly by simply extruding a synthetic profile, preferably with linear development, or by 3D or injection moulding. The synthetic profile compared to known systems is therefore economical, lightweight and easily customisable in size and characteristics to suit design requirements.

The profile comprises a support wall and a side wall having respective inner faces inclined towards each other according to an angle of inclination that is lower than or equal to 90° so as to define, during a configuration of use of the element, a soil retaining surface.

Advantageously, the “two-wing” (or “shelf”) geometry of the profile of the modular element makes it possible to prevent tilting of the profile also during laying operations.

Thanks to its slim geometry, the profile is also easy for operators to transport and move on site.

Advantageously, the support wall has, on a lower face opposite with respect to the inner face thereof, a first coupling element, whereas the side wall has, at a free end edge thereof, a second coupling element that is counter-shaped with respect to the first, so as to allow for the coupling of at least two modular retaining elements to form a retaining wall without interruptions (i.e. continuously, with continuity, uninterruptedly, without interruptions).

In other words, each profile of a retaining element can be coupled to another profile via the interface defined by the coupling elements, which are arranged on opposite sides of the side walls. It is therefore sufficient to couple several profiles vertically in sequence to obtain a retaining wall.

Thanks to the modular retaining element according to the present invention, it is possible to realise a complete facing closure (by coupling the first and second coupling elements) that allows each upper element to be integral with the lower one. This type of configuration allows for a closed wall facing that allows for no migration of fine material or retaining material to the rear and minimises the infiltration/passage of fluids (e.g. water).

In a second aspect, the invention provides a kit for building a retaining wall of soil comprising:

- a plurality of modular elements in accordance with the first aspect of the present invention, which can be coupled sequentially to each other so that the support walls of the profiles are arranged parallel to each other, and the first coupling element of a respective profile is coupled to a second coupling element of a subsequent second profile to create a seamless retaining wall; and

- soil reinforcement means suitable to be interposed between the soil and the modular elements.

Advantageously, the kit is structurally simple and quick to install.

Preferably, the modular element is produced simply by an extrusion (or coextrusion) process of a die/line profile, or by 3D printing or injection moulding, in a highly customisable manner, and is designed to be laid horizontally, i.e. in “horizontal layers”, so that the main development axis X is essentially horizontal.

In the creation of retaining walls and embankments or reinforced soils in civil, environmental, hydraulic, geotechnical and mining engineering, the “facing” of the retaining wall, i.e. the outer surface of the wall that will not be in contact with the soil but will be visible, will therefore be defined by the side walls of the coupled profiles (which can be customised in size and finish according to design or architectural requirements).

The profile can in fact be coated with different aesthetic finishes or colours. It is also usually combined with various reinforcing elements of the prior art (such as geogrids, geotextiles, geostrips, but also metal reinforcements or bar or rope anchors) to meet a wide variety of requirements.

The invention can be used as a substitute for retaining wall or reinforced soil solutions of the prior art, typically for the creation of road embankments, noise barriers, rockfall valleys, counterscarp walls, masking works and for the construction of banks or embankments. They are also ideally used in hydraulic barrier projects, in bank defence, in the creation of canals and riverbeds, and in general, in urban regeneration projects, for road works and in the railway sector.

The dependent claims herein incorporated for reference, correspond to different embodiments of the invention.

Further characteristics and advantages of the present invention will appear more clearly from the indicative, and therefore non-limiting, description of a preferred but not exclusive embodiment of a modular retaining element for soil retaining walls and the related kit, as illustrated in the accompanying drawings.

Brief description of the drawings

Figure 1 is a schematic section of a modular retaining element for retaining walls in accordance with the present invention.

Figures 1 a and 1 b are simplified schematic views of the element in Figure 1 in accordance with two possible construction variants of the step.

Figure 2 is a schematic perspective view of the retaining element of figure 1 in which some optional stiffening walls are also visible. Figures 3a-3e schematically illustrate possible embodiments of connection means of a kit for building a soil retaining wall in accordance with the present invention.

Figure 4 is a schematic perspective view of the retaining element of figure 1 , showing two possible embodiments of the connection means illustrated in figures 3a and 3d.

Figures 5a-5f schematically show possible ways of coupling different embodiments of retaining elements according to the present invention.

Figure 6 and Figure 7 show retaining walls made through two possible embodiments of the kit according to the present invention.

Figure 8 shows the use of an extension bar of the kit according to the present invention.

Detailed description of preferred embodiments of the invention

With reference to the appended figures, a modular retaining element for building retaining walls W of soil G, henceforth simply retaining element 1 , has been collectively referred to as 1 , and a kit for building retaining walls of soil G, henceforth simply kit 100, has been collectively referred to as 100.

The retaining element 1 comprises a synthetic profile 2 developing along a main development axis X and having a plurality of inner chambers C.

It should be noted that the term “profile” is intended to denote a technical element with a much smaller thickness than the other dimensions, i.e. a slim element.

Preferably also the synthetic profile is a synthetic polymer profile, even more preferably extruded or co-extruded.

In particular, when using the extrusion process, the main development axis X is preferably coincident with the extrusion direction of the profile 2.

Preferably the inner chambers C develop along development directions parallel to the main development axis X.

Preferably the inner chambers C are empty in order to make the element 1 lighter and more manageable.

The inner chambers C are preferably substantially rectangular or square, but may vary in shape according to the design and thus the stresses (typically compression) to which the element 1 is subjected. Preferably, the volume occupied by the plurality of chambers is comprised between 10% and 90% of the total volume of the synthetic profile 1 .

The profile 2 comprises a support wall 3 and a side wall 4 having respective inner faces 3’, 4’ inclined towards each other according to an angle of inclination a that is lower than or equal to 90° so as to define, during a configuration of use of the retaining element 1 , a soil retaining surface G.

In other words, as will become clearer later in the description, once the element 1 is installed, the inner faces 3’, 4’ will be in contact with ground G to contain it. The weight of the soil G resting on the horizontal inner face 3’ will prevent the overturning of the element 1 , which will therefore remain in a stable position with the side wall 4 defining the retaining of the built wall.

In particular, the side wall 4 has an outer face 4’ opposite to the respective inner face 4’ of the side wall 4 and defining the outer surface of the element 1 as well as the wall W.

The support wall 3 has, on a lower face 3” opposite to the respective inner face 3’ of the support wall 3, a first coupling element 5, and wherein said side wall 4 has, at a free end edge 4a of the side wall 4, a second coupling element 6 that is counter-shaped with respect to the first coupling element 5, so as to allow for the coupling of at least two modular retaining elements 1 to form a retaining wall W without interruptions.

According to one possible embodiment, the lower face 3” of the support wall 3 has a rough surface finish or a plurality of reliefs to increase the shear resistance between the modular element 1 and the soil G.

Preferably, the synthetic profile 2 is made from a polymer matrix, either virgin or from recycled and/or biopolymers, or from other recycled materials or plywood. Preferably, the synthetic profile 2 is of a composite type, reinforced with glass fibre or carbon fibre to ensure the necessary compressive strengths. The fibre-reinforced profile 2, for example, allows the profile to be stiffened at the points subject to the most critical stresses.

The use of recycled materials in the creation of the profile 2 allows for significant advantages in sustainability, carbon footprint and CO2 emission reductions.

The morphology, geometry and material characteristics of the profile 2 may vary according to the performance required by the project: according to the loads it must withstand, the aggressiveness of the environment in which it is to be laid (e.g. marine, or high pH environments), or the expected durability (possible addition of special additives), whether it is to be fireproof, whether it is to be coated, or hooked, nailed, glued with a facing covering, etc. Advantageously, the invention allows a high level of customisation and adaptability to different environmental conditions, but also aesthetically, as the profile 2 is very versatile in design and use.

Preferably the side wall 4 and the support wall 3 define a substantially L- shaped profile, in which the angle of inclination is preferably equal to 90°.

According to a possible alternative embodiment, illustrated for example in Figure 5c, preferably the angle of inclination a may be comprised between 45° and 90° so that the side wall 4 and support wall 3 define a profile essentially in the shape of an overturned “V”.

This makes it possible to build inclined, i.e. non-vertical, retaining walls W to meet a wide variety of design requirements.

As illustrated in figure 1 , preferably the first coupling element 5 is made at the corner edge 34 of the profile 2, i.e. at the junction between the side wall 4 and the support wall 3.

In accordance with an alternative embodiment of the profile 2, illustrated in Figure 5f, the side wall 4 and the support wall 3 define a profile 2 essentially in the shape of an inverted “T”, in which the angle of inclination a is preferably equal to 90°. In other words, the side wall 4 extends perpendicularly away from the inner face 3’ of the support wall 3 from a central area of the support wall itself 3, or at least not at the end edges.

It is also possible to build inclined, i.e. non-vertical, retaining walls W in which the inclination is provided by the horizontal offset between the side wall 4 and the outer end edge 3a of the retaining wall 3.

In addition, preferably the profile 2 may comprise an outer wall 7 extending away from the support wall 3, preferably parallel to the side wall 4, so as to define an angular edge 37 of the profile 2 at which the first coupling element 5 is made. In other words, the corner edge 37 is made at the outer end edge 3a of the support wall 3.

Advantageously, a pocket 8 is defined between the side wall 4, the support wall 3 and the outer wall 7, which can be used, for example, for decorative reasons such as creating pockets of vegetation or creating drainage channels or for the passage of fluids (water)

With reference to Figure 5a, the element 1 preferably also comprises a cladding panel 8 applicable to the outer face 4” of the side wall 4.

According to a possible embodiment, not illustrated in the appended figures, the cladding panel 8 can also - or alternatively - be applied to the outer wall 7.

The element 2 is therefore highly customisable.

In particular, the profile 2 allows various external finishes with textures or other aesthetic patterns (wood effect, slats, etc.); through the insertion of a surface during the extrusion process or through moulding or marking still during extrusion, a finish of other material co-extruded in the production line at the factory onto the outer surface 4” is obtained. Depending on the design requirements and demands of the end customer, this cladding can be applied retrospectively by means of gluing, screwing onto the profile, or by means of a specially created interlocking on the profile 2.

With reference to Figure 2, the element 1 may further preferably comprise at least one stiffening wall 9 interposed or suitable to be interposed transversely, preferably perpendicularly, between the support wall 3 and the side wall 4 to stiffen the structure of the profile 2.

If significant loads are present, such as for example from direct bridge abutments or cranes acting on the wall, advantageously the invention allows for further stiffening of the profile 2 through the use of stiffening walls 9, i.e. brackets or shaped elements capable of engaging or being embedded into the profile 2.

The number of stiffening walls 9 and their thickness (which can be measured parallel to the direction X) can be selected according to design requirements and operating loads.

According to the present invention, the profile 2 may have an average thickness, measured perpendicular to the main development axis X, comprised between 20 mm and 80 mm, even more preferably 40 mm.

The modular element 1 can also typically have a height of 30 cm (i.e. height of the side wall 4) and a width of 20 cm (i.e. width of the support wall 3), and a length (measured along the direction X) which varies according to the design, preferably comprised between 5 m and 13 m.

The element 1 therefore makes it possible to cover large lengths with low weights; unlike the blocks of the prior art that are laid on short sections a few tens of centimetres and weigh several tens of kilos. In addition, these elements can be transported more efficiently with respect to systems of the prior art (more square metres of wall on a truck or container than traditional methods).

With reference to Figure 5b, preferably the first coupling element 5 may be a pin and the second coupling element 6 may be a groove counter-shaped with respect to said pin 5, so that the first and second coupling elements 5, 6 can be coupled together to make an interlock.

Advantageously, the interlocking coupling allows for a more solid and watertight wall with improved speed of execution.

In accordance with a possible embodiment of the element 1 illustrated in the appended figures, for example with reference to Figure 1 , the support wall 3 of the profile 2 may have, at a free end edge 3a of the support wall 3, a step 10 extending parallel to the main development axis X along the entire support wall 3 and extending perpendicularly away from the support wall 3, even more preferably parallel to the side wall 4.

Advantageously, the step 10 is very useful for coupling the element 1 with the soil G retaining means, as will become clearer in the description below. Preferably, the step 10 extends perpendicularly to the support wall 3 by a stretch comprised between 40mm and 60mm.

Preferably, the step 10 also extends from the support wall 3 in the same direction as the side wall 4; alternatively, it could also extend in the opposite direction (Figure 1 a), advantageously allowing further engagement of element 1 with the ground (thus increasing shear strength and friction/slip resistance). According to a possible further alternative embodiment, illustrated in Figure 1 b, preferably the step 10 could also extend in both directions to form a “T” shape, allowing both engagement with the ground and with the retaining means.

With reference to Figures 3d and 4, preferably the step 10 has a sequence of passage holes 11 (only one hole 11 is shown in Figure 4 for illustrative simplicity) having a length, measured parallel to the main development axis, between 50 mm and 220 mm and arranged at a variable distance depending on how many reinforcements (typically geo-strips) are required to ensure the stability of the work W.

In other words, the passage holes 11 have an elongated shape, i.e. they extend parallel to the main development axis X.

Advantageously, the passage holes 11 can be used to connect the element 1 with the retaining means of the soil G (reinforcements), as will become clearer in the description below.

Preferably opposite side ends 2’ of the profile 2 have respective horizontal coupling elements, not illustrated in the appended figures, counter-shaped to each other in order to create a horizontal coupling of consecutive elements 1 arranged along a direction parallel to the main development axis X.

In other words, the elements 1 can be easily coupled together horizontally to define a stable and watertight wall.

Also forming part of the present invention is a kit 100 for building a retaining wall W of soil G comprising:

- a plurality of modular retaining elements 1 according to the present invention which can be coupled sequentially to each other so that the support walls 3 of the profiles 2 are arranged parallel to each other, and wherein the first coupling element 5 of a respective profile 2 is coupled to a second coupling element 6 of a subsequent profile 2 to create a retaining wall W without interruptions; and

- soil reinforcement means 101 suitable to be interposed between the soil and the modular retaining elements.

In other words, with reference to Figures 6 and 7, the elements 1 are stacked vertically to create the wall W, so that the support walls 3 rest horizontally on the ground W and the side walls 4 are substantially vertical to externally define the facing of the wall W and internally the retaining of the soil G.

In particular, the method of laying the wall W using the kit 100 involves proceeding in layers. The height of profile 2 is in fact designed to be proportional to the layers of soil laid and compacted in layers, typically 30 cm.

Figure 6 shows an example of a pre-existing escarpment of land GO which has been consolidated/retained/reinforced by means of the kit 100 according to the present invention for building the wall W. The first element 1 is first laid so that its support wall 3 is horizontal; in particular, the first element 1 is laid at “zero level”, i.e. at formation or foundation level, at a certain distance from the inclined escarpment GO, as per the design. A layer of soil G1 is then placed in the space between the side wall 4 and the escarpment GO until the elevation at the second coupling element 6 of the element 1 is reached. Then a further element 1 is laid so that the respective first coupling element 5 is coupled to the second coupling element 6 of the previously laid element, and the filling operations for G2 are repeated. This is done in layers G1 , G2, G3, G4 until the defined level is reached according to the design.

It should be noted that after placing the element 1 and before proceeding with the soil filling, reinforcement means 101 are also installed to make the soil cooperate with elements 1 .

With reference to Figure 5d, preferably the modular element 1 may have a recess 4b at the free end edge 4a of the respective side wall 4 of the profile 2. In this case in particular, the kit 100 may comprise at least one longitudinal spacer strap 102 suitable to be interposed, in use, parallel to the main development axis X, between the recess 4b of a respective modular retaining element 1 and the first coupling element 5 of a subsequent modular retaining element 1 to form an inclined retaining wall W.

In other words, the longitudinal spacer strap 102 allows for an angle of inclination of the wall W that can vary depending on the width of the strap 102.

As illustrated for example in Figure 5e also preferably the wall W can also be made in an inclined manner by coupling the coupling elements 5, 6 in a staggered manner, thus varying the conformation of the coupling elements 5, 6, while maintaining horizontal positioning of the support walls 3. The solution illustrated in figure 5c also provides for this type of staggered coupling, but combined with elements 1 having side walls 4 inclined with respect to the support walls 3 by an angle of inclination lower than 90°.

With reference to Figures 3a-3d, 4, 6, preferably the reinforcement means 101 comprise sheets, nets or strips (e.g. geogrids, geotextiles, geostrips, geo-nets or wire meshes) that can be connected to the support walls 3 of the profiles 2 by means of connection means 103 and are suitable to be arranged in use within the soil G parallel to the support walls 3. The connection means 103 can either make a frictional connection (Figure 3b) or a positive connection (Figures 3a, 3c, 3d). The positive or frictional connection affects the performance of the retaining wall or reinforced soil because it acts on the sliding (or pullout) resistances of the blocking/reinforcement system.

In other words, the sheets or strips separate the layers of soil G1 , G2, G3, G4.

Preferably the connection means 103 may be selected from:

- adhesives (Figure 3b shows schematically a sheet/strip glued to the element 1 at the inner faces 4’, 3’);

- nails, pins or pivots (Figure 3c schematically illustrates a sheet/strip nailed to the element or connected by inserting a pin or pivot into a hole created in the element 1 at the inner face 3’, to create a mechanical fastening to increase the pull-out resistance of the element-reinforcement system and thus the resistance to loads of the element-reinforcement system);

- counter-shaped brackets to the steps 10 of the support walls 3 (Figure 3a and Figure 4 below schematically illustrate a sheet/strip surmounting the step 10 and clamped on it by means of a point bracket or continuous bar bracket to the element 1 at the inner faces 4’, 3’, to create a mechanical interlocking fastening to increase the pull-out resistance of the element-reinforcement system and thus the resistance to loads of the elementreinforcement system);

- passage holes 11 made in steps 10 of the support walls 3 for the turn-up of the sheets or strips 101 (Figure 3d and Figure 4 above schematically shows a sheet/strip 101 turned up inside the passage hole 11 ).

According to a possible embodiment not illustrated, the sheet/strip 101 connection with the element 1 can be frictional, i.e. by simple friction: the sheet/strip 101 is laid on top of the modular element 1 and turned up before being covered with the soil G (as illustrated in Figure 3b, but without adhesive). The reinforcement is then simply placed and turned up on the facing 4 to contain the soil laid on top.

Preferably, with reference to Figure 7, reinforcement means 101 comprise steel rods, e.g. bars or ropes.

With reference to Figure 8, the reinforcement means 101 of the kit 100 may comprise a plurality of extension bars 104 (only one bar 104 is visible in the side view of Figure 8) suitable to be arranged in use parallel to the support walls 3 of the modular retaining elements 1 , so as to advantageously increase the footprint of the support walls 3 in applications where there is not enough space around the area of intervention, i.e. around the wall/ground to be reinforced, to lay sheeting or wire mesh. Typically, this situation occurs in the case of low walls (less than 100 cm high) around which there is no space to excavate and lay reinforcing sheeting or netting, so it is necessary to extend the footprint of the supporting walls 3 of elements 1 to increase the stability of the new retaining wall that will be created.

In particular, each extension bar 104 has a coupling portion 104a configured to engage in use with a step 10 of the support wall 3 to connect them together and thus locally extend the support wall 3.

Preferably the bars 104 are made of the same material as the elements 1 . Preferably, the bars 104 have a length (predominant dimension), measured parallel to the support wall 3 of the element 1 less than 1000 mm and a width, measured parallel to the axis X, less than 100 mm. Further, the bars are preferably arranged at a distance of 1000 mm from each other.

Finally, the kit may preferably include a vertical joining element, not illustrated, suitable to be interposed between horizontal coupling elements, not illustrated, of consecutive retaining elements 1 arranged horizontally along a direction parallel to the main development axis X, creating a joint capable of obviating possible problems of thermal expansion or micromovements of the soil.

The present invention achieves the proposed aims by overcoming the drawbacks complained of in the prior art and by providing an extremely versatile and cost-effective modular retaining wall element and kit for building a retaining wall that is practical to install and efficient.

Claims

1. Modular retaining element (1 ) for retaining walls (W) of soil (G) comprising a synthetic profile (2) developing along a main development axis (X) and having a plurality of inner chambers (C), wherein said synthetic profile (2) comprises a support wall (3) and a side wall (4) having respective inner faces (3’, 4’) inclined towards each other according to an angle of inclination (a) that is lower than or equal to 90° so as to define, during a configuration of use of the retaining element (1 ), a soil retaining surface, wherein said support wall (3) has, on a lower face (3”) opposite to the respective inner face (3’) of the support wall (3), a first coupling element (5), and wherein said side wall (4) has, at a free end edge (4a) of the side wall (4), a second coupling element (6) that is counter-shaped with respect to the first coupling element (5), so as to allow for the coupling of at least two modular retaining elements (1 ) to form a retaining wall (W) without interruptions.

2. Modular retaining element (1 ) according to claim 1 , wherein said side wall (4) and said support wall (3) define a substantially “L”- shaped synthetic profile (2), said angle of inclination (a) being preferably equal to 90°.

3. Modular retaining element (1 ) according to claim 2, wherein said first coupling element (5) is made at the corner edge (34) of the synthetic profile (2).

4. Modular retaining element (1 ) according to claim 1 , wherein said side wall (4) and said support wall (3) define a synthetic profile (2) substantially having an inverted-"!"” shape, said angle of inclination (a) being preferably equal to 90°.

5. Modular retaining element (1 ) according to claim 4, wherein said synthetic profile (2) comprises an outer wall (7) extending away from the support wall (3), preferably parallel to the side wall (4), so as to define a corner edge (37) of the synthetic profile (2) at which the first coupling element (5) is made.

6. Modular retaining element (1 ) according to one of the preceding claims, wherein said inner chambers (C) are empty.

7. Modular retaining element (1 ) according to one of the preceding claims, wherein the volume occupied by the plurality of chambers (C) is between 10% and 90% of the total volume of the synthetic profile (2).

8. Modular retaining element (1 ) according to one of the preceding claims, comprising a cladding panel (8) applicable to an outer face (4”) of the side wall (4) opposite the respective inner face (4’)-

9. Modular retaining element (1 ) according to one of the preceding claims, comprising at least one stiffening wall (9) interposed or suitable to be interposed transversely, preferably perpendicularly, between the support wall (3) and the side wall (4) to stiffen the structure of the synthetic profile (2).

10. Modular retaining element (1 ) according to one of the preceding claims, wherein said synthetic profile (2) has an average thickness, measured perpendicularly with respect to the main development axis (X), having a value between 40 mm and 80 mm, preferably equal to 40 mm.

11. Modular retaining element (1 ) according to one of the preceding claims, wherein said first coupling element (5) is a pin and wherein said second coupling element (6) is a groove countershaped with respect to said pin, said first and second coupling elements (5, 6) being couplable to each other to make an interlock.

12. Modular retaining element (1 ) according to one of the preceding claims, wherein said support wall (3) has, at a free end edge (3a) of the support wall (3), a step (10) extending parallel to the main development axis (X) along the entire support wall (3) and perpendicularly away from the support wall (3), preferably parallel to the side wall (4).

13. Modular retaining element (1 ) according to claim 12, wherein said step (10) has a sequence of passage holes (11 ) having a length, measured parallel to the main development axis (X), between 50 mm and 220 mm.

14. Modular retaining element (1 ) according to one of the preceding claims, wherein the lower face (3”) of the support wall (3) has a rough surface finish or a plurality of reliefs.

15. Modular retaining element (1 ) according to one of the preceding claims, wherein opposite side ends (2’) of said synthetic profile (2) have respective horizontal coupling elements that are counter-shaped with each other to make a horizontal coupling of consecutive retaining elements (1 ) arranged along a direction parallel to the main development axis (X).

16. Kit (100) for building a soil (G) retaining wall (W) comprising:

- a plurality of modular retaining elements (1 ) according to one of the preceding claims which can be coupled sequentially to each other so that the support walls (3) of the extruded plastic profiles (2) are arranged parallel to each other, and wherein the first coupling element (5) of a respective synthetic profile (2) is coupled to a second coupling element (6) of a subsequent synthetic profile (2) to create a retaining wall (W) without interruptions; and

- soil (G) reinforcement means (101 ) suitable to be interposed between the soil (G) and the modular retaining elements (1 ).

17. Kit (100) according to claim 16, wherein the modular retaining element (1 ) has, at the free end edge (4a) of the respective side wall (4) of the synthetic profile (2), a recess (4b), and wherein the kit (100) comprises at least one longitudinal spacer strap (102) suitable to be interposed, in use, parallel to the main development axis (X), between the recess (4b) of a respective modular retaining element (1 ) and the first coupling element (5) of a subsequent modular retaining element (1 ) to form an inclined retaining wall (W).

18. Kit (100) according to claim 16 or 17, wherein said reinforcement means (101 ) comprise sheets, nets or strips which may be connected to the support walls (3) of the extruded plastic profiles (2) by means of connection means (103) and are suitable to be arranged in use within the soil (G) parallel to the support walls (3).

19. Kits (100) according to claim 18, wherein said connection means (103) may be optionally selected from: adhesives, nails, braces that are counter-shaped to steps of the support walls (3), passage holes (11 ) made in steps (10) of the support walls (3) to make the flap of the sheets, nets or strips.

20. Kit (100) according to claim 16 or 17, wherein said reinforcement means (101 ) comprise steel rods, for example bars or ropes.

21. Kits (100) according to claim 16 or 17, wherein said reinforcement means (101 ) comprise a plurality of extension bars (104) adapted to be arranged in use parallel to the support walls (3) of the modular retaining elements (1 ), each extension bar (104) having an engagement portion (104a) configured to engage in use with a step (10) of the support wall (3).