FR3092853A1 - Process for creating an artificial basin with natural purification - Google Patents

Abstract

Method of making d 'a artificial pond with natural purification The present invention relates to a method of making an artificial basin (100) comprising: a step of constructing a sloping bottom (10); a step of applying a waterproofing layer (20) on the bottom; a step of laying an intermediate layer of geotextile (70b); a step of applying a stabilization layer (40) over the intermediate geotextile layer; a step of laying an upper layer of geotextile (70c) on the stabilization layer; a step of distributing a layer of sand (50) over the top layer of geotextile; and a step of filling the artificial basin with a volume of water (60). The method further comprises a step of installing drainage means between the waterproofing layer and the sand layer. The invention also relates to an artificial basin produced by this process. Figure for the abstract: figure 6

Description

Process for creating an artificial basin with natural purification

The present invention belongs to the general field of artificial pools, in particular artificial ornamental and swimming pools inspired by ponds and other natural bodies of water. The invention relates more particularly to a method for producing an artificial basin with natural purification.

State of the art

Artificial pools intended for ornamental and/or recreational use are known, they can be above ground, or, for the most part, dug. These two categories will be considered interchangeably given the nature of the invention. These basins include, on the one hand, swimming pools, characterized by their built structure and by the masonry materials and the various means implemented in their construction, and on the other hand, natural-looking basins, which are similar ponds, lagoons, ponds, etc.

Natural-looking artificial pools, which will simply be referred to as artificial pools, are distinguished from swimming pools mainly by a bottom made of non-rigid natural material such as sand or earth, and by the absence of built-up edges in favor of beaches. horizontal or substantially sloping artificial structures.

The methods for producing this type of artificial pond generally include the following steps:

- Dig the basin following a determined shape in terms of contour on the ground and depth;

- Install a network of pipes, connection and sealing to a filtration unit;

- Position a geotextile material on the bottom, the walls and the peripheral beach;

- Position a geomembrane material on the geotextile material;

- Clamp equipment and accessories for sealing the pool;

- Spread a layer of sand over the entire surface covered by the previous layers; and

- Fill the basin.

By way of example, European patent EP1922457B1 discloses a method for constructing ponds, swimming pools and small artificial lakes in general, comprising steps of implementing a waterproofing layer, applying filters, ducts, entrances and exits, collection channels, and covering the internal walls and/or the bottom of the container thus obtained with stones distributed on the waterproofing layer.

A pool obtained with such a process has a major drawback, namely the formation of algae favoring the alteration of the appearance of the stones. In addition, the use of sand in such a process would cause the sand to rot and make the pond unsuitable for swimming.

To destroy microorganisms, bacteria, algae or fungi contained in pond water, a known method consists of filtering the water to remove solid organic matter and either adding powerful oxidants such as hypochlorites or hypobromites. sodium or potassium, or to generate these products by electrolysis of chloride or bromide. It is also known to use photocatalytic compositions for the purification of pond water.

These chemical solutions have a certain harmfulness and can be dangerous both for bathers, in the case of bathing pools, and for animal species, in the case of pond-type ornamental pools.

There are natural water purification solutions such as lagooning, however, their implementation remains quite complex for pools intended mainly for swimming.

Presentation of the invention

The present invention aims to overcome the drawbacks of the prior art, by proposing a method making it possible to obtain a basin with a bottom capable of preventing the sand from blackening and rotting, thanks to a circulation of the water which minimizes its stagnation. , the sand remaining practically in its original state.

To this end, the present invention relates to a method for producing an artificial pool comprising:

- a stage of construction of a sloping bottom;

- a step of applying a waterproofing layer on the bottom;

- a step of laying an intermediate layer of geotextile;

- a step of applying a stabilization layer over the intermediate layer of geotextile;

- a step of laying an upper layer of geotextile on the stabilization layer;

- a step of spreading a layer of sand over the top layer of geotextile; and

- a step of filling the artificial basin with a volume of water.

Each layer completely covers the layer before it. The method further comprises a step of installing drainage means between the sealing layer and the layer of sand.

The method further comprises a step of defining the shape of the artificial basin before the step of excavating and terracing the ground.

Advantageously, the stabilization layer is based on material in granules of mineral origin such as limestone.

According to one embodiment of the invention, the method comprises, between the step of applying the waterproofing layer and the step of laying the intermediate layer of geotextile, in order:

- a step of laying a lower layer of geotextile on the waterproofing layer; and

- a step of applying a separation layer over the lower layer of geotextile;

According to this same embodiment, the sealing layer is clay-based.

More particularly, the sealing layer consists of a first sub-layer of compacted clay and a second sub-layer of compacted clay, each of said sub-layers being applied independently of the other and compacted by means of a steamroller for example.

Advantageously, the separation layer is based on material in granules of mineral origin having a particle size smaller than a particle size of the stabilization layer.

According to another embodiment of the invention, the method comprises a step of laying a lower layer of geotextile on the surface of the excavation before the step of applying the sealing layer, and the layer of waterproofing is a geomembrane.

Advantageously, the drainage means are connected to a filtered water recovery tank.

The invention also relates to an artificial basin of any shape comprising an excavation, a beach and a volume of water at least partially filling said excavation, produced by a method as described above.

The fundamental concepts of the invention having just been explained above in their most elementary form, other details and characteristics will emerge more clearly on reading the description which follows and with regard to the appended drawings, giving by way of illustration non-limiting example an embodiment of a method in accordance with the principles of the invention.

Presentation of drawings

The different figures as well as the elements of the same figure are not necessarily represented at the same scale. In all the figures, identical elements bear the same reference numeral.

It is thus illustrated in:

:: a schematic perspective view of an artificial basin according to the invention;

: a perspective section of the artificial basin of FIG. 1;

: a succession of sections representing a progressive realization in superimposed layers of the artificial basin;

: the main steps of the method according to the invention, each step being opposite the corresponding section in FIG. 3;

: a section of the artificial pool according to one embodiment of the invention;

: a detail of Figure 5;

: a partial section of the artificial pool according to a preferred embodiment of the invention.

Detailed description of embodiments

The terminology employed in the present invention should in no way be construed in a limiting or restrictive manner, simply because it is employed in conjunction with a detailed description of particular embodiments of the invention.

In the embodiment described below, reference is made to a method for producing an artificial pool intended mainly for use in the field of ornamental and leisure pools. This non-limiting example is given for a better understanding of the invention and does not exclude the implementation of the method in other fields such as the installation of aquatic culture basins and the like.

FIG. 1 represents an artificial basin 100 in the form of a pond made by a method according to the invention. This artificial basin, dug in the ground S, consists mainly of an excavation 10, the bottom of which is visible in broken lines in the figure, of a volume of water 60 filling said excavation, at least partially, and defining a body of water 61, and a terraced beach 51 on the edge of excavation 10.

The term "excavation" is used interchangeably to designate both the operation of digging the ground and the very result of this operation.

The excavation 10, in accordance with the invention, can have various shapes and sizes. Thus, the artificial basin 100 whose dimensions and overall shape result from those of the excavation 10 can have a regular shape of the frustoconical type, with or without steps, or any irregular shape such as that shown in FIG. 1. In addition, the excavation 10 has side walls inclined with respect to the vertical to the ground so as to form a downward slope, which allows for example access to the bottom of the basin 100 from the range 51 when the latter is shallow.

The beach 51 overcomes and surrounds the excavation 10 while presenting a continuity with the ground S, and allows, moreover, to visually delimit the artificial basin 100 by providing an advantageous aesthetic approval.

The body of water 61 defines an outline 62 which corresponds to the water filling level of the artificial basin 100 and which thereby has a shape identical to that of a peripheral curve, or iso-depth, of the excavation 10. For a more harmonious rendering and a more natural effect, the area 51 has an outline 52 whose shape recalls that of the outline 62 of the body of water 61. Preferably, the area 51 is of a substantially constant width all around of the body of water 61, said width being defined by the distance between the two contours 52 and 62.

The artificial basin 100 according to the invention comprises a superposition of layers 20 to 50, represented in FIG. 2, covering the entire surface of the excavation 10. Each of these layers has specific characteristics, more particularly in terms of nature. , composition and thickness, which allow it to fulfill a determined function according to its position in the stack as detailed in the following description.

FIG. 2 also represents a recovery station 200 to which the artificial basin 100 is connected, said station makes it possible to recover, store and return to the basin the water naturally filtered by certain layers at the bottom of the basin. To this end, the recovery station 200 mainly comprises a pipeline 210, a reservoir 220 and a pumping and distribution system, not shown.

The pipeline 210 connects the artificial basin 100 to the reservoir 200, and comprises drainage means at its end placed at the level of the basin and a water outlet at its other end opening into the said reservoir, the transfer of water by the pipeline taking place by gravity. The means of drainage must cover a major part of the bottom of the basin, for example, they can consist of pipes arranged in loops and pierced in their upper part.

The tank 220 is buried in the ground S and can either be built in situ like a pit, or simply installed by being manufactured, prefabricated or ordered on demand. This reservoir allows the storage of filtered water 230 which will be used to supply the artificial basin 100 again thanks to the pumping and distribution system.

Basically, the specific function of the recovery station 200 is known and represents the downstream phase of the water purification cycle of the artificial basin. The upstream phase corresponds, for its part, to the filtration of the water in the basin by means of a particular arrangement of layers, the subject of the present invention, described below.

Alternatively, the filtration of the pool water can be carried out entirely at the level of the recovery station, which would also be a filtration station, with different filtration techniques known to those skilled in the art.

The method according to the invention makes it possible to define and order the operations necessary for the realization of the artificial basin 100, and this, from the topographic design of said basin to its impoundment.

With reference to Figures 3 and 4, the method of making the artificial pool according to one embodiment of the invention mainly comprises:

- an initial step 500 of defining the shape 10-0 of the excavation 10;

- a step 510 of excavation and earthwork of the ground according to the defined shape;

- a step 520 of coating the excavation 10 with a sealing layer 20, said step comprising:

- a first step 521 of applying a first sub-sealing layer 521; and

- a second step 522 of applying a second sub-sealing layer;

- a step 527 of laying a geotextile on the sealing layer 20 obtained;

- a step 530 of applying a separation layer 30 over the geotextile laid in the previous step;

- a step 537 of laying a geotextile on the separation layer 30 obtained;

- a step 540 of applying a stabilization layer 40 over the geotextile laid in the previous step;

- a step 547 of laying a geotextile on the stabilization layer 40 obtained;

- a step 550 of distributing a layer of sand 50 over the geotextile laid in the previous step;

- a final step 560 of filling the basin with the volume of water 60 required.

The aforementioned steps constitute an embodiment of the method according to the invention and can be supplemented by secondary steps known to those skilled in the art such as steps of conditioning, treatment and finishing of the surfaces of the different layers.

The initial step 500 consists of making a topographic plan of the excavation 10 and tracing an outline of said excavation on the ground from the topographic plan. This plan represents a view of the excavation in three dimensions, the shape thus obtained can be broken down into a closed contour on which rests a three-dimensional surface corresponding to the bottom and the side walls of the excavation. Only the outline of the excavation can be physically traced on the ground, the three-dimensional surface which corresponds to the excavation itself is obtained by digging, earthmoving and earth clearance operations according to the rules of the art.

Step 510 consists of excavating the earth from the outline drawn in the previous step and following a precise topographic plan to obtain the desired shape in terms of depth, slopes, overall concavity, etc., and terracing the soil so as to obtain the desired range. This step also makes it possible to prepare the ground for the application of the successive layers constituting the bottom of the artificial basin.

The first of these layers is applied during step 520 which consists in coating the excavated and terraced surface with a sealing layer 20. According to the illustrated embodiment, the sealing layer 20 is composed of two sub-layers sealing, lower 21 and upper 22, stacked for improved waterproofing of the artificial pool. Thus, step 520 is broken down into a step 521 of applying the lower sealing layer 21 and a step 522 of applying the upper sealing layer 22 as illustrated in Figures 3 and 4.

For example, each waterproofing layer is clay-based. Preferably, compacted clay is used. The use of clay makes it possible to achieve a natural waterproofing that resists various external aggressions, unlike geomembranes often used for the simplicity of their installation but which nevertheless present a vulnerability to openings for example. The superposition of two layers of compacted clay makes it possible to ensure impermeability for soils of different consistencies, in particular, in the case of unstable soil, for which a single layer of clay, even of significant thickness , cannot suffice. Indeed, the superposition of two layers makes it possible to create an interface between said layers which limits the propagation of cracks from one layer to another. Clay compaction can be done by different methods such as dry compaction using a steamroller. In addition, the double layer of waterproofing adapts perfectly to a relatively irregular bottom, lined with small pebbles for example, by covering the pebbles and soil particles with the lower layer, and smoothing the whole thing with the upper layer.

Step 527 consists in covering the sealing layer 20 with a layer of geotextile material in order to separate it from the layer which will be deposited in the next step.

The step 530 of applying the separation layer 30 consists in covering the previous layers, waterproofing 20 and geotextile, with a material in granules.

The separation layer 30, according to one embodiment of the invention, is based on aggregates of mineral origin having a small particle size. Preferably, the separation layer 30 is based on limestone.

Step 537 consists in covering the separation layer 30 with a layer of geotextile material, which is then positioned “as a sandwich” between two geotextile layers.

The step 540 of applying a stabilization layer 40 consists in depositing on the previous layers a layer of a material in granules having a particle size greater than that of the separation layer 30.

The stabilization layer 40, according to one embodiment of the invention, is of mineral origin and consists of crushed elements, of gravel type, which make it possible to stabilize the lower layers.

Step 547 is similar to step 537 and makes it possible to cover the stabilization layer 40 with a layer of geotextile material.

Step 550 consists of spreading a layer of sand 50 over all the previous layers so as to form the bottom and the beach of the artificial pool. The layer of sand 50 thus covers the sloping edges of the basin to form the beach 51 and join the ground as illustrated in Figures 1 and 2.

In the last step, the artificial basin is filled during step 560 with a volume of water 60 adapted to obtain the most natural aesthetic result possible.

In addition, the method according to the invention comprises a step of installing the pipe 210 provided with drainage means, between the bottom of the basin and the reservoir 220 as shown in FIG. 2. These drainage means must be placed at the level of the separation layer 30, more precisely, between the sealing layer 20 and said separation layer, above the deepest geotextile layer.

The production of the reservoir 220 can be the subject of an independent step carried out before the method of production of the artificial basin.

The final result of the stacking of the aforementioned layers is visible in partial section of the basin in Figure 5. For better clarity, the thicknesses of the different layers in this figure are not to scale.

Figure 6 makes it possible to distinguish the different layers of the artificial basin, according to one embodiment of the invention, which comprise in order the first sealing layer 21, the second sealing layer 22, the lower geotextile 70a, the separation layer 30, the intermediate geotextile 70b, the stabilization layer 40, the upper geotextile 70c, the sand layer 50 and the water 60.

As a result of this advantageous arrangement of the layers listed above, the water in the pond undergoes natural filtration which begins with a passage through the layer of sand 50 which purifies the water by a sieving action allowing the retention of organic matter. This organic matter is degraded by microphytes present in the sand and favored by the freshwater environment represented by the artificial basin, the pathogenic micro-organisms are thus eliminated. Then the water passes through the stabilization layer 40, made up of mineral gravel, which then carries out a first filtration of the water by retaining suspended matter and limiting certain heavy metals and minerals. The water is filtered one last time in the separation layer 30, which has a smaller particle size than the stabilization layer 40, before being drained into the recovery tank 220 and returned to the artificial basin.

Added to this is the filtering effect of geotextiles 70a, 70b and 70c, the use of geotextiles in the production of filter beds being known.

Each geotextile also fulfills a specific function depending on its position in the stack of layers of the artificial basin. The lower geotextile 70a makes it possible to protect the lower side of the drainage means, and to avoid any contact between the granules of the separation layer 30 and the sealing layer 20 in order to preserve the smooth texture of said sealing layer. The intermediate geotextile 70b makes it possible to isolate the separation layer 30 from the stabilization layer 40, and the upper geotextile 70c makes it possible to prevent the infiltration of sand 50 into the stabilization layer 40.

FIG. 7 represents a partial section of the artificial basin according to a particularly advantageous embodiment in which the sealing layer 20 is a geomembrane, based on polyethylene, polypropylene or polyvinyl chloride for example, placed above a geotextile bottom 70a, and in which the separation layer 30 is eliminated. According to this alternative embodiment, the method for producing the artificial pool comprises:

- an initial stage of defining the shape of the excavation;

- a stage of excavation and earthwork of the ground according to the defined shape;

- A step of laying the lower geotextile 70a;

- a step of laying the waterproofing geomembrane 20;

- a step of laying an intermediate geotextile 70b on the geomembrane 20;

- a step of applying the draining stabilization layer 40 over the intermediate geotextile;

- a step of laying an upper geotextile 70b on the stabilization layer 40 obtained;

- a step of distributing the layer of sand 50 over the upper geotextile;

- a final stage of filling the basin with the volume of water 60 required.

According to this embodiment, the drainage means must be arranged at the level of the stabilization layer (40), and more precisely just above the intermediate geotextile (70b).

It emerges from the description of the present invention that additional steps, usual for those skilled in the art, can be added to the method for producing the artificial pool, and that certain steps can be performed differently without thereby departing from the scope of the invention.

For example, the artificial pond can be constructed above ground according to steps equivalent to those of the embodiments described. In this case, the excavation and earthworks stages would be replaced by masonry-type construction stages.

Claims (10)

A method of making an artificial basin (100), characterized in that it comprises: a step of constructing a sloping bottom (10); a step of applying a waterproofing layer (20) on the bottom; a step of laying an intermediate layer of geotextile (70b); a step of applying a stabilization layer (40) over the intermediate geotextile layer; a step of laying an upper layer of geotextile (70c) on the stabilization layer; a step of distributing a layer of sand (50) over the top layer of geotextile; and a step of filling the artificial basin with a volume of water (60); each of said layers entirely covering the layer preceding it, said method further comprising a step of installing drainage means between the waterproofing layer (20) and the sand layer (50). A method according to claim 1, wherein the step of constructing a bottom corresponds to a step of excavating and grading the soil, making it possible to obtain a sloping excavation. A method according to claim 2, further comprising a step of defining the shape of the artificial pond (100) before the step of excavating and grading the ground. A method according to any one of the preceding claims, wherein the stabilizing layer (40) is based on granular material of mineral origin. Method according to any one of the preceding claims, characterized in that it comprises, between the step of applying the waterproofing layer (20) and the step of laying the intermediate layer of geotextile (70b), in order: a step of laying a lower layer of geotextile (70a) on the waterproofing layer; and a step of applying a separation layer (30) over the bottom layer of geotextile; and in that the waterproofing layer is clay based. A method according to claim 5, wherein the waterproofing layer (20) consists of a first sub-layer of compacted clay (21) and a second sub-layer of compacted clay (22), each of said sub-layers being applied independently of the other and compacted by means of a road roller. A method according to claim 5 or claim 6, wherein the separation layer (30) is based on granular material of mineral origin having a particle size smaller than a particle size of the stabilization layer (40). Method according to one of claims 1 to 4, characterized in that it comprises a step of laying a lower layer of geotextile (70a) on the bottom or the surface of the excavation (10) before step d application of the waterproofing layer (20), and in that the waterproofing layer is a geomembrane. A method according to any preceding claim, wherein the drainage means are connected to a tank (220) for collecting the filtered water (230). Artificial basin (100) of any shape comprising an excavation (10), a beach (51) and a volume of water (60) at least partially filling said excavation, characterized in that it is produced by a method according to one of the preceding claims.