3d-printed fish ladder comprising successive pools

Abstract

The invention relates to fish ladders comprising successive pools, and to a method for the additive manufacturing of a fish ladder comprising successive pools.

Description

3D printed successive pool fish pass

[0001] The invention relates to successive-basin fish passes, in particular successive-basin fish passes constructed by additive manufacturing. The invention also relates to a method for additive manufacturing a successive-basin fish pass.

[0002] The state of the art document "Fish passes; expertise and design of crossing structures" by Messrs. Larinier, Porchet, Travade and Gosset - Collection mise au Point, 1996, which constitutes a reference work in the field of fish passes, is already known.

[0003] For the proper functioning of the main phases of their biological cycle, certain fish species need different living environments and must move to reach their reproduction or fattening areas. It is essential for these species to maintain free movement so as not to disrupt their migration because it is an essential phase of their survival; and this, whether for downstream migration (from upstream to downstream) and / or especially for upstream migration (from downstream to upstream). However, the construction of obstacles, among which we will cite for example navigation dams, water intake dams and river weirs, has been and still is the main factor responsible for the decline or even the disappearance of migratory fish species.

[0004] The field is complex because it requires taking into account a very large number of factors related to the obstacle to be crossed, whether for an existing or new structure. Although essential, the geometric characteristics and knowledge of the hydraulic conditions on and at the foot of the structure, in particular the drop height, must be accompanied by numerous other data / knowledge / studies to successfully carry out any crossing project. The constraints will be as much structural (topography, bathymetry, equipment and networks, available space) as functional (hydrology, hydraulics, hydrobiology, environmental status, fish passability, etc.) as legislative and / or regulatory, requiring multidisciplinary teams for each crossing project. The function of a crossing device is to ensure the passage of fish at the obstacle, "fish continuity".The principle is either to open a waterway to bypass the obstacle, for example the dam (fish pass), or to trap the fish before transporting them and releasing them upstream of the structure (elevator, etc.).

[0005] Solutions for maintaining or regaining longitudinal river connectivity include basin and pre-dam passes, slowdown passes, "natural" passes, lifts and locks, and eel passes.

[0006] The invention relates to fish passes with successive basins.

[0007] The principle of the successive-basin fish pass is to divide the total drop of the obstacle, for example the dam, into a series of falls, in order to form a hydraulic staircase compatible with the swimming capacity of the fish, said capacity being a function of the species, the size of the individuals as well as the temperature of the water. The falls are controlled by vertical partitions which separate the basins, said basins allowing to dissipate the energy of the fall and to provide a resting area for the fish.

[0008] The invention aims in particular to respond by a single means of manufacture to the various constraints of producing fish passes with basins while providing numerous advantages as they will be described in the description which follows.

[0009] To this end, the invention relates to a fish pass with successive basins having walls formed of more than 25% of curved surfaces relative to their total surface area, said walls being made up of a superposition of layers of mortar and / or concrete by additive manufacturing.

[0010] According to a particular optional feature of the fishway, the superposition of layers is a superposition of layers of at least one double extrudate of mortar and / or concrete by additive manufacturing. A double extrudate layer of mortar and / or concrete constitutes an important optional feature as illustrated in the rest of the text and figures; its production by additive manufacturing makes it possible to produce walls that meet mechanical strength and water flow objectives while satisfying requirements related to the passage of fish. The fact that the walls are thus made of superimposed double extrudate layers implies that the walls are in reality double walls as illustrated in the rest of the text and figures. In one embodiment, the fishway with successive basins is characterized in that the double extrudate is contiguous.In another embodiment, the fish pass with successive basins is characterized in that the double extrudate comprises a space between the extrudates which can be filled with mortar and / or concrete; the function of the mortar and / or concrete, which will be, for illustrative purposes, different from that used for the additive manufacturing of the wall extrudates, will be to give the double wall a structural resistance responding to particular constraints encountered in the field.

[0011] According to a particular optional feature of the fish pass, the extrudate is essentially continuous, preferably continuous. By essentially continuous, it is understood that the implementation of the additive manufacturing process of the extrudate avoids any discontinuity of said extrudate. Exceptional discontinuities, generally linked to additive manufacturing operating problems, may be tolerated without this departing from the invention. By way of illustration, less than ten, or even five extrudate discontinuities will be tolerated per basin, for example less than four, less than three, less than two, or even no discontinuities per basin. By way of illustration, less than ten, or even five extrudate discontinuities will be tolerated per pass, for example less than four, less than three, less than two, or even no discontinuities per pass.

[0012] Depending on other optional features of the fish pass taken alone or in combination:

[0013] – each basin consists of walls, a bottom, an inlet and an outlet;

[0014] – over the entire wall height above the inlet and outlet sluice height, the two opposite ends of the double extrudate form a continuous curved surface. Additive manufacturing will thus be controlled so as not to generate an angular zone during the formation of the double extrudate. This characteristic has proven relevant not only for improving water flow but also for the longevity and general efficiency of the fish pass at the point where fish must pass between the basins;

[0015] – the walls of the fish pass basins are made up of more than 50% curved surfaces, more than 75%, or even more than 99% of their total surface area. This characteristic of getting as close as possible to an absence of sharp angles in the design of the basin walls has proven relevant for improving water flow as well as for the longevity and general efficiency of the fish pass;

[0016] – the top view (horizontal projection) of the walls of each basin is a closed curve with variable curvature; for example, the curve may include positive and negative curvature; for example, the curve will include less than 50% straight part, or even less than 25% straight part, or even no straight part;

[0017] - the top view (horizontal projection) of the outer walls of the pass is a closed curve with variable curvature; for example, the curve may include positive and negative curvature; for example, the curve will include less than 50% straight part, or even less than 25% straight part, or even no straight part;

[0018] - the walls of the basins are essentially vertical, for example vertical;

[0019] – the inlet of a basin corresponds to the outlet of the basin which precedes it in the direction of water flow;

[0020] – two successive basins share at least part of their wall.

[0021] The invention also relates to a method for the additive manufacturing of a fish pass with successive basins having walls formed of more than 25% of curved surfaces relative to their total surface area and consisting of a superposition of layers of at least one double extrudate of mortar and / or concrete, the double extrudate being formed by essentially continuous extrusion of mortar and / or concrete by layer.

[0022] By essentially continuous, it is understood that the implementation of the additive manufacturing process of the extrudate avoids any discontinuity of said extrudate. Exceptional discontinuities, generally linked to problems of additive manufacturing operation, may be tolerated without this departing from the invention. By way of illustration, less than ten, or even five extrudate discontinuities will be tolerated per basin, for example less than four, less than three, less than two, or even no discontinuities per basin. By way of illustration, less than ten, or even five extrudate discontinuities will be tolerated per pass, for example less than four, less than three, less than two, or even no discontinuities per pass.

[0023] Additive manufacturing, also known as 3D printing, is a method in which a computer-controlled robot creates three-dimensional objects by continuously depositing material layer upon layer.

[0024] In this text, concrete or mortar refers indifferently to a material comprising a hydraulic binder and aggregates. In general, the wet mortar, obtained by mixing a dry mortar and mixing water, is pumped and conveyed to a print head attached to a robot or a gantry whose movement is controlled by a computer. A layer of wet mortar is deposited on a layer of mortar previously deposited, generally by being extruded through a nozzle. The print head is continuously moved according to a predetermined pattern in order to manufacture the walls layer after layer, each layer being formed of a double contiguous extrudate or with space between each extrudate by essentially continuous extrusion of mortar and / or concrete. The nozzle is advantageously guided along three axes x, y, z to allow the manufacture of the walls.The different layers are created by translation, in height / along the z axis, or rotation of the print head and therefore of the nozzle. This translation along the Z axis by a defined distance allows each increment to deposit the appropriate quantity and thickness of material.

[0025] The method therefore preferably comprises a step of mixing a dry mortar composition with water in order to obtain a wet mortar of pasty consistency. The wet mortar is preferably pumped and conveyed, generally in a pipe, to the print head of a printer. The print head comprises in particular a nozzle through which the wet mortar is extruded. The extrusion nozzle is preferably located less than 100 mm from the underlying layer. The printer is for example an industrial robot or a gantry, carrying the print head, and the movement of which is controlled by a computer. The computer comprises in particular a recording medium in which a set of data or 3D model is stored as well as instructions, which when executed by the computer lead the latter to control the movement (trajectory, speed, etc.) of the print head.

[0026] According to other optional characteristics of the additive manufacturing process of a fish pass with successive basins taken alone or in combination:

[0027] – the double extrudate, the double extrudate layers and the corresponding walls are formed using a single extrusion head with a single extrusion nozzle;

[0028] - the printing (or extrusion) speed is typically 30 to 1000 mm / s, especially 50 to 300 mm / s;

[0029] - the thickness (or height, since this refers to the dimension in the vertical direction) of the mortar layers is between 5 and 40 mm, in particular between 10 and 20 mm;

[0030] - the width of a mortar extrudate is between 10 and 300 mm, in particular between 20 and 100 mm;

[0031] - in section in a plane transverse to the walls, in other words in the plane of the mortar layers, the thickness of the walls is between 20 and 600 mm, in particular between 60 and 240 mm. A greater thickness is possible, in particular in the case of spacing between the extrudates in order to serve as formwork. Brief description of the figures

[0032] The invention will be better understood on reading the following description, given solely by way of example and with reference to the appended drawings in which:

[0033] is a three-dimensional view of a fish pass.

[0034] is a set of top views of an illustration of the additive manufacturing implementation strategy of the fish pass of the.

[0035] is a top view of the fish pass.

[0036] is a three-dimensional view of a fish pass.

[0037] is a view of a cross-section of the fish pass along axis AA shown in the. Detailed description

[0038] A three-dimensional illustration of a fish pass is shown, which comprises respectively an upstream basin, six successive basins and a downstream basin in the direction of water flow. In this illustration, the upstream and downstream basins are not necessarily part of the fish pass as claimed, since they may well illustrate the entry and exit points (for example of the river or watercourse) which are connected by the fish pass to six successive basins.

[0039] The six successive basins consist of walls, a bottom, an inlet sluice and an outlet sluice. The inlet sluice of a basin corresponds to the outlet sluice of the basin which precedes it in the direction of water flow. The walls of the six successive basins of the pass are vertical and have curved surfaces. In one embodiment, the difference in vertical elevation of the upper parts of the walls of the basins is generally between 15 and 70 cm between two successive basins.

[0040] In the illustration according to the, the bottoms of the basins are not shown; in reality, their vertical elevation will depend on the design of the pass and its requirements, including the volume of water that each successive basin must contain. In one embodiment, the difference in vertical elevation of the upper parts of the bottoms of the basins is generally between 15 and 70 cm between two successive basins.

[0041] The height of the walls of each basin will depend on the design of the pass and its requirements, including the volume of water that each successive basin must contain; the total height of the walls may then depend on the ground and / or the support on which the structure must be placed as illustrated in the in which the construction of all the walls begins at an identical level of vertical elevation, which we will call zero elevation for descriptive purposes. This illustration helps to show the importance of using additive manufacturing in the design and construction of the fish pass as explained by means of the.

[0042] This is a set of top views of an illustration of the additive manufacturing implementation strategy for the fishway. This figure includes 16 sub-figures, which are read first from left to right and then from top to bottom, and which illustrate 16 stages of manufacturing the fishway, each corresponding to the additive manufacturing of a height of all the walls of the fishway concerned by this height. The first stage represented by the first sub-figure corresponds to a top view of the fishway because it represents the first height of all the walls of the fishway located above the zero elevation; this first height of the walls will also be called the first slice in this text.

[0043] As shown in the first figure in connection with the second figure, the 16 superimposed slices of the walls correspond to the 16 printing stages, each successive stage corresponding to a wall height at identical elevation; thus, the sixteenth slice corresponding to the sixteenth printing stage during which the last wall elevation is carried out, in this case that of the upstream basin as shown in the figures.

[0044] Printing continuity between each step is preferred to avoid any discontinuity of extrudate when printing the entire walls of the basins. This continuity guarantees the geometry of the curved surfaces of the walls; it also allows the two opposite ends of the double extrudate to form a continuous curved surface over the entire height of the wall greater than the height of the inlet and outlet slits.

[0045] Although the double extrudate is preferred, it is obvious that the walls could be made with multiple extrudates, for example with triple or quadruple extrudates, in a particular embodiment depending on the mechanical resistance constraints linked to the design of the fish passage structure to be produced.

[0046] The double extrudate principle illustrated in the figures made it possible to meet the requirements of continuity and curved surfaces of the walls.

[0047] The figures, and in particular the top views (horizontal projection) of the walls of each basin, illustrate the principle of a closed curve with variable curvature, of essentially vertical walls and of the fact that two successive basins share at least part of their wall.

[0048] The mortar preferably comprises a hydraulic binder and aggregates.

[0049] Wet mortar, which has a pasty consistency, is formed by mixing dry mortar with water. Dry mortar is a powdery mixture. After setting and hardening, the final mortar is called hardened mortar, or "concrete."

[0050] The mixing ratio, i.e. the ratio between the quantity of mixing water and the quantity of dry mortar (by weight), can be adjusted if necessary or be the same for all walls. The mixing ratio is preferably at most 0.5, in particular between 0.05 and 0.20. The wet mortar has a pasty consistency and can be pumped and transported to the print head. Pumping is carried out, for example, by means of a screw pump. Transport is typically carried out in a pipe. The transport device therefore preferably comprises a pump, in particular a screw pump, as well as at least one pipe.

[0051] The hydraulic binder is preferably selected from Portland cements, aluminous cements, sulfoaluminous cements, hydrated lime, ground granulated blast furnace slag, fly ash and mixtures thereof. The hydraulic binder preferably comprises a Portland cement. It is advantageously made of Portland cement.

[0052] The aggregates are preferably chosen from siliceous, calcareous, dolomitic aggregates and mixtures thereof. The maximum size of the aggregates is preferably at most 3 mm, in particular at most 2 mm and even at most 1 mm, taking into account the reduced section of the pumping device and the nozzle of the print head.

[0053] The dry mortar preferably comprises at least one additive, in particular chosen from superplasticizers, thickeners, accelerators and retarders. The dry mortar advantageously comprises inorganic thickeners, for example swelling clays, capable of increasing the yield strength of the wet mortar at rest. The accelerators and retarders make it possible to adjust the time required for the hydraulic binder to set and harden. The composition of the dry mortar is preferably adjusted so that the wet mortar exhibits thixotropic behavior. Preferably, the viscosity of the wet mortar increases by a factor of at least 50 only one second after the wet mortar leaves the printing nozzle.The wet mortar then has a low viscosity at high shear rates so that it can be easily pumped and conveyed, but has an immediate increase in its structural stability as soon as it leaves the nozzle of the print head, thus supporting the overlying layers before setting and hardening. This deposition on a layer of still wet mortar improves the adhesion between successive layers, and therefore the final mechanical strength of the wall. In contrast, conventional processes use accelerators to greatly accelerate the setting and hardening of the mortar so as to deposit on layers of mortar that has already set or hardened, which ensures dimensional stability during printing but at the expense of adhesion between successive layers.

[0054] Continuous deposition also improves adhesion between each extrudate when they are contiguous, which contributes to the mechanical resistance of the double wall.

[0055] The method involves the successive deposition of superimposed layers of mortar. As previously indicated, the layers are preferably deposited on an underlying layer that has not yet set or hardened.

[0056] The mortar layers are advantageously dense and capable of fulfilling their structural role. Preferably, the density after hardening (particularly after 28 days) of the mortar layers of the walls is at least 2000 kg / m 3 , in particular at least 2100 kg / m 3 This density is preferably less than or equal to 2500 kg / m 3 .

[0057] In a particular embodiment, additive manufacturing has made it possible to produce a fish pass whose wall roughness characteristics have demonstrated their usefulness in improving water flow as well as for the longevity and general efficiency of the fish pass. This roughness was measured using the classic roughness parameters Ra, Rq, Rz. The profilometer used is a Keyence LJ-X8400. The zero is set arbitrarily relative to the sample-laser distance. The lateral laser pitch is 100µm with a total width of 29mm. The laser scan pitch is 75µm with a total scan length of 81.7mm. The scan area is approximately 3x8cm with approximately 300 lines of 8cm length.This type of measurement demonstrated that a roughness having values ​​between plus or minus 30% of the following values ​​could advantageously be used in the present invention: a value of Ra (µm) of 85 and / or a value of Rq (µm) of 106 and / or a value of Rz (µm) of 442.

[0058] Figures 3a, 3b and 3c show another fish pass, respectively by means of a top view, a three-dimensional view and a cross-sectional view along the axis AA shown in the.

[0059] These representations correspond to a practical case of the construction of a fish pass, the characteristics of which are indicated in the following table.

[0060]

[0061] Basins 7 and 0 are respectively the upstream and downstream basins, which are in reality a representation of the entry and exit points (for example of the river or watercourse in the direction of water flow) which are connected by the fish pass to six successive basins.

[0062] The elevations indicated in the table correspond to absolute elevations of the project considered. The surface column indicates the free surface of the water in m 2in each basin. The notch dimension corresponds to that of the sluices of each basin. The bottom dimension corresponds to that of each basin. The water dimension corresponds to the elevation of the upper surface of the water for a water flow corresponding to 63 liters per second. The volume of water in m3 corresponds to that of each of the 6 successive basins. The previous basin drop corresponds to the difference in water level between two successive basins; as illustrated in the second table, it depends on the water flow. The dissipated power density is in W / m 3 ; this criterion of energy dissipation per basin corresponds to the formula “Pv = ρ g Q DH / V” with Pv: Dissipated volumetric power (watts / m3) ρ: density of the water (1000 kg / m 3 ) g: acceleration of gravity (9.81 m / s²) Q: flow rate in the structure (m 3 / s) DH: drop between basins (m) and V: volume in the basin (m 3 ).

[0063] The second table differs from the first because the data corresponds to a water flow rate of 53 liters per second.

[0064]

[0065] The positioning of the sluices in the walls of the basins is advantageously carried out so that the orientation of the water flows through the sluices of the basins does not disturb the presence of a calming zone within each of the basins.

[0066] The invention is not limited to the embodiments presented and other embodiments will become clear to those skilled in the art. It is in particular possible to design passes with more or fewer successive basins depending on local constraints.

Claims

Fish pass with successive basins having walls formed of more than 25% curved surfaces in relation to their total surface area, said walls being made up of a superposition of layers of mortar and / or concrete by additive manufacturing. Fish pass with successive basins according to claim 1, the walls of which are made up of a superposition of layers of at least one double extrudate of mortar and / or concrete by additive manufacturing. Fish pass with successive basins according to claim 2 characterized in that the double extrudate is contiguous. Fish pass with successive basins according to claim 2 characterized in that the double extrudate comprises a space between the extrudates filled with mortar and / or concrete. Fish pass with successive basins according to any one of the preceding claims, the walls of which are formed of more than 50% curved surfaces relative to their total surface area. Fish pass with successive basins according to claim 5, the walls of which are formed of more than 75% curved surfaces relative to their total surface area. Fish pass with successive basins according to claim 6, the walls of which are formed of more than 99% curved surfaces relative to their total surface area. Fish pass with successive basins according to any one of the preceding claims, the top view of the outer walls of the pass being a closed curve with variable curvature. Fish pass with successive basins according to any one of the preceding claims, the walls of the basins of which are vertical. Fish pass with successive basins according to any one of the preceding claims, each basin consisting of walls, a bottom, an inlet sluice and an outlet sluice, the inlet sluice of a basin corresponding to the outlet sluice of the basin which precedes it in the direction of water flow. Fish pass with successive basins according to any one of the preceding claims, two successive basins of which share at least part of their wall. Fish pass with successive basins according to any one of the preceding claims, the measured roughnesses Ra, Rq and / or Rz of which are between plus or minus 30% of 85 µm for Ra and / or between plus or minus 30% of 106 µm for Rq and / or between plus or minus 30% of 442 µm for Rz. Method for additive manufacturing of a fish pass with successive basins according to any one of the preceding claims, the basins having walls formed of more than 25% of curved surfaces relative to their total surface area and consisting of a superposition of layers of at least one double extrudate of mortar and / or concrete, the double extrudate being formed by essentially continuous extrusion of mortar and / or concrete by layer. A method of additive manufacturing a fish pass with successive basins according to claim 13 wherein the double extrudate, the double extrudate layers and the corresponding walls are formed using a single extrusion head with a single extrusion nozzle.

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