Method and device for making the bottom of a water flow area impermeable.

Abstract

A method for impermeable the bottom (3) of a provided water flow area (1) to a dike (2) made of concrete or natural soil, comprising spreading a substrate (4) of an inert mineral material on the bottom (3) of the water flow area (1), the method comprising: - creating grooves (6) in each interface region (11) between the substrate (4) of the water flow area (1) and the dike (2), each groove extending longitudinally along each dike (2); - spreading impermeable coating elements (5) on the substrate (4) and inserting the impermeable coating elements (5) into each groove (6) to form each bend (7) in each groove (6); and - fixing the impermeable coating elements (5) to the dike (2) of the water flow area (1) using fixing elements (16). An impermeable device for making the bottom (3) of a body of water (1) impermeable, comprising an impermeable coating element (5) configured to be spread on a substrate (4) made of an inert mineral material spread on the bottom (3) of a water flow region (1), and comprising at least one support layer (13) and an impermeable layer made of a composite material (14), wherein a portion of the impermeable coating element is folded to form a bent portion (7) that can be inserted into a groove (6) extending within the interface region between the bottom (3) of the water flow region (1) and a dam (2).

Description

Technical Field

[0001] The present invention relates to a method and a device for impermeabilizing natural or artificial watersheds having natural soil or concrete dams, wherein the bottom and the dams of the watershed may undergo deformations caused by interaction with water in the watershed, differential settlement, earthquake events or other causes, thereby resulting in relative movement between the concrete dams and the bottom of the watershed, which generally consists of soil or rock, and the bottom is covered with a mineral material base layer to obtain a flat, compact and homogeneous bottom.

[0002] (Prior Art) It is known to impermeabilize the bottom of an artificial or natural watershed by spreading an impermeable membrane that extends to the bottom of the watershed up to the dams of the watershed, for example dams made of concrete or dams made of excavated and thus strongly compacted materials to which a membrane is fixed.

[0003] To obtain a flat, compact, homogeneous and smooth substrate, the bottom of the watershed can be covered with a mineral material base layer on which the impermeable membrane can be spread and fixed or simply placed.

[0004] The dams of the watershed and the substrate of the bottom of the watershed exhibit different behaviors with respect to mechanical stresses caused, for example, by the action of water present in the watershed or by movements originating from the earth, and due to ground settlement movements that are and are not caused.

[0005] In fact, while the dams of the watershed are relatively rigid, the substrate of the bottom of the watershed can be considered an elastic layer, and thus the deformations suffered by the substrate at the bottom of the watershed due to mechanical stresses are much larger than the deformations of the dams considering the same stress.

[0006] When the aforementioned deformation occurs, the impermeable membrane, which is integrated with the substrate at the bottom of the watershed and is used for the water load and any possible fixed systems or ballast for the embankment, is subjected to deformation stress that can reach values ​​that cause the impermeable membrane to break, resulting in the loss of impermeability at the bottom of the watershed. [Overview of the project] [Problems that the invention aims to solve]

[0007] The objective of the present invention is to provide impermeability to the bottom of natural or artificial watersheds by an impermeable membrane, thereby eliminating the risk of damage to the impermeable membrane caused by deformations of varying magnitudes experienced by the bottom of the watershed and the dam due to mechanical stress. [Means for solving the problem]

[0008] The object of the present invention is achieved by the method for making the bottom of a water flow area impermeable according to claim 1, and the impermeable device according to claim 6.

[0009] In particular, according to a first aspect of the present invention, a method is provided for making the bottom of a water flow area impermeable, comprising: providing a groove in the interface region between the bottom of the water flow area and the embankment; spreading an impermeable covering element on the bottom of the water flow area; inserting the impermeable covering element into the groove; forming a bent portion; and fixing the impermeable covering element to the embankment of the water flow area using fixing means.

[0010] According to another aspect of the present invention, an impermeable device comprises at least one support layer and an impermeable layer made of a composite material, wherein a portion of the covering device is folded to form a bent portion, which is inserted into a groove extending in the interface region between the bottom of a watershed and a levee.

[0011] The presence of a bent section inserted into a groove at the interface between the bottom of the watershed and the embankment within the impermeable coating allows the coating to compensate for any deformation of varying magnitudes that may occur in the bottom of the watershed and the embankment. In fact, the bent section allows the coating to extend without being subjected to tensile stress due to the aforementioned deformation, thus eliminating the risk of coating failure. [Brief explanation of the drawing]

[0012] Further features and advantages of the present invention will become apparent from the following description of embodiments of the invention, provided as non-limiting examples with reference to the accompanying drawings. [Figure 1] This is a schematic cross-sectional view of the bottom of a water flow area and a levee, illustrating the installation of the impermeable coating device according to the present invention. [Figure 2] This is a detailed enlarged view of Figure 1. [Figure 3] This is a cross-sectional view similar to Figure 1, showing a modified example of the installation of the water-impermeable coating device according to the present invention. [Modes for carrying out the invention]

[0013] Figure 1 shows a schematic cross-section of a water flow area 1 having a concrete dam 2.

[0014] At the bottom 3 of the water flow region 1, a substrate 4 made of an inert mineral material is spread, and on top of it, an impermeable covering element 5 consisting of a highly flexible geomembrane 14 made of a composite material having, for example, layers of PVC, PVC with ELVALOY, TPO, or EPDM is spread, which can be thermally laminated with a layer of nonwoven geotextile material. A layer 13 of a support material made of an ultra-low deformation industrial fiber material that acts as a mechanical support for the geomembrane 14 is located beneath the geomembrane 14.

[0015] Industrial fiber materials can be woven geosynthetic materials containing high-toughness polypropylene multifiber yarns, woven in a stable mesh to maintain relative position.

[0016] The interface region 11 between the substrate 4 and the dam 2 in the water flow region 1 is provided with two grooves 6 that extend longitudinally along the dam 2.

[0017] The water-impermeable coating element 5 is inserted into the groove 6, forming a bent portion 7 in each of the grooves 6, which includes a first straight portion 9 facing the substrate 4, a second straight portion 10 facing the dam 2, and a curved portion 12 connecting the first straight portion 9 to the second straight portion 10.

[0018] Each bent portion 7 forms an accumulation portion of an impermeable coating element, which is suitable for compensating for relative movement between the substrate 4 and the dam 2, for example, due to ground subsidence, the action of water present in the watershed, or movements originating from the Earth.

[0019] In each groove 6, a strip 8 made of a nonwoven geotextile material or another material with a low coefficient of friction (e.g., PTFE) is placed between the first straight portion 9 and the second straight portion 10 of the bent portion 7, and the strip 8 is folded over itself to form a further bent portion, and is positioned to maintain the mutually facing surfaces of the bent portion 7, i.e., the mutually facing surfaces of the first straight portion 9 and the second straight portion 10, in a separated state.

[0020] The strip 8, made from nonwoven geotextile material, has a low coefficient of friction, which is arranged to facilitate the mutual sliding of the mutually facing surfaces of the bent portion 7, avoiding damage and wear thereto, and allowing the first straight portion 9 and the second straight portion 10 of the bent portion 7 to slide against each other substantially without friction, and as a result the impermeable coating element 5 can move to compensate for the deformation of the substrate 4 and the ridge 2 without being subjected to tensile stress that could jeopardize its integrity.

[0021] The waterproofing covering element 5 is fixed to the dam 12 through a plurality of fixing elements 16, and the plurality of fixing elements 16 are, for example, spaced apart from each other at a substantially constant pitch and themselves have a metal profile for distributing the force fixed by metal pins fixed to corresponding holes made in the dam 2 of the water catchment area in a known manner.

[0022] Figure 3 shows a variant of the method according to the invention, which variant provides for spreading a layer 15 of ballast made of a waterproofing material (for example, bituminous concrete or cement-based concrete) on the covering element 5, as a result of which the covering element 5 is blocked between the substrate 4 and the layer 15 made of the waterproofing material.

[0023] In this case, the geomembrane 14 made of a composite material can consist of a film made of PVC, PVC with ELVALOY, TPO, or laminated EPDM and includes layers of non-woven geotextile material on both sides.

[0024] The waterproofing material of the ballast layer 15 absorbs the fibers of the upper layer of the non-woven geotextile material when it is spread on the geomembrane 14 and obtains a waterproof bond between the two materials.

[0025] The invention can also be used for the connection between two rigid structures that can move independently of each other. The substrate 4 can consist of plastic, asphalt, or granular material, which deteriorates over time until it no longer exists, and thus voids may be obtained. In this case, the reinforcing layer 13 made of non-woven geotextile material prevents the geomembrane 14 from deforming beyond the breaking limit.

[0026] In this solution, the bottom 3 can consist of a bituminous mastic, PVC, or a copper waterstop.

Claims

1. A method for making the bottom (3) of a water flow region (1) impermeable, comprising spreading a substrate (4) of an inert mineral material on the bottom (3) of the water flow region (1), - A step of creating grooves (6) in each interface region (11) between the substrate (4) and the embankment (2) in the water flow region (1), wherein each groove extends longitudinally along each embankment (2), - The steps of spreading the impermeable coating element (5) on the substrate (4), inserting the impermeable coating element (5) into each of the grooves (6), and forming each of the bent portions (7) in each groove (6) to form an accumulation portion of the impermeable coating element (5) suitable for compensating the relative movement between the substrate (4) and the dam (2), - A step of inserting a strip (8) made of a nonwoven geotextile material, PTFE, or equivalent material, folded on itself, positioned to maintain the mutually facing surfaces of the bent portion (7) in a separated state, the strip (8) made of a nonwoven geotextile material or PTFE having a low coefficient of friction, which is positioned to facilitate the mutual sliding of the mutually facing surfaces of the bent portion (7) and to avoid damage / wear thereto, into each of the grooves (6) between the first straight portion (9) and the second straight portion (10) of each of the bent portions (7); A method comprising the step of fixing the impermeable covering element (5) to the embankment (2) of the water flow area (1) using a fixing element (16).

2. The method according to claim 1, wherein the impermeable coating element (5) is made of a geomembrane (14) comprising layers of PVC, PVC having ELVALOY, TPO, or EPDM.

3. The method according to claim 2, further comprising thermal laminating a layer of at least one nonwoven geotextile material onto the layer of PVC, PVC having ELVALOY, TPO, or EPDM.

4. The method according to claim 3, further comprising thermal lamination of each layer of nonwoven geotextile material to opposing surfaces of the layers of PVC, PVC having ELVALOY, TPO, or EPDM.

5. The method according to any one of claims 2 to 4, further comprising positioning the geomembrane (14) on a reinforcing layer (13) made from an industrial fiber material.

6. The method according to any one of claims 1 to 5, further comprising spreading a layer of impermeable material (15) on the impermeable coating element (5).

7. An impermeable device for making the bottom (3) of a water flow area (1) impermeable, comprising an impermeable coating element (5) configured to be spread on a substrate (4) of an inert mineral material spread on the bottom (3) of the water flow area (1), comprising at least one support layer (13) and an impermeable layer (14) made of a composite material, wherein a portion of the impermeable coating element is folded to form a bent portion (7), which can be inserted into a groove (6) extending within the interface region (11) between the bottom (3) of the water flow area (1) and the embankment (2), and the part of the bent portion (7) An impermeable device comprising: a strip (8) of nonwoven geotextile material, PTFE, or equivalent material, folded over itself, inserted between a first straight portion (9) and a second straight portion (10), positioned to maintain the separation of the mutually facing surfaces of the bent portion (7); the strip (8), made of nonwoven geotextile material, PTFE, or equivalent material, having a low coefficient of friction, and positioned to facilitate the mutual sliding of the mutually facing surfaces of the bent portion (7) and to prevent damage or wear thereto.

8. The water-impermeable device according to claim 7, wherein the water-impermeable coating element (5) comprises a geomembrane (14) having a layer of PVC, PVC having ELVALOY, TPO, or EPDM.

9. The impermeable device according to claim 8, wherein at least one layer of nonwoven geotextile material is thermally laminated onto the layer of PVC, PVC having ELVALOY, TPO, or EPDM.

10. The impermeable device according to claim 9, wherein each layer of nonwoven geotextile material is thermally laminated onto opposing surfaces of the said layers of PVC, PVC having ELVALOY, TPO, or EPDM.

11. The water-impermeable device according to any one of claims 8 to 10, wherein the geomembrane (14) is fixed to a lower support layer (13) made of industrial fiber material.

12. The impermeable device according to any one of claims 7 to 11, wherein the impermeable covering element (5) is fixed to the embankment (2) of the water body (1) using a fixing element (16).

13. The impermeable device according to any one of claims 7 to 12, further comprising a layer (15) made of an impermeable material, particularly bituminous concrete or cement, spread on the impermeable coating element (5).

14. The impermeable device according to claim 15, wherein the nonwoven geotextile material laminated on the geomembrane (14) is absorbed by the bituminous concrete or the cement, creating a strong, impermeable bond between the two materials.

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