CN1294647A - Pressurized liquid circulation duct and method for prodn. thereof - Google Patents

Abstract

The invention relates to a liquid circulation duct comprising a pipe (1) that is fixed to a solid, rigid support (B) in order to form a base that rests on a standing surface (C). The pipe (A) is made of a thin resistant wall that forms a tight tubular enclosure. On each side of the longitudinal axis (O, O'), the solid, rigid support (B) is provided with a single-piece component (31, 31') having an L-shaped profiled cross-section comprising a substantially vertical branch (32) that extends along a corresponding side of the enclosure (A) and a substantially horizontal branch (33) that extends underneath the latter, forming at least one part of the base (3) of the solid support (B) that rests upon the ground.

Description

Pressurized fluid circulation pipe and manufacturing method thereof

The present invention relates to a fluid circulation pipeline which can be buried under a roadbed, in particular to a circulation pipeline for high-pressure fluid with a pressure of several bar.

The invention relates in particular to pipe structures with very large cross-sectional areas, for example greater than 2 m ² , but can also be used well for pipe structures of ordinary dimensions.

The invention also relates to a method of constructing the pipeline.

The fluid conveying pipes can simply be produced in the form of metal or concrete pipe units and butt-connected, the ends of these pipe units being inserted into each other by inserting joints. When subsiding, some units may become loose and experience higher pressures. For example, for pressurized delivery pipes of hydroelectric power stations, it is preferable to use metal pipe units welded at their adjacent ends.

In this case, the duct is constructed from prefabricated duct units or curved panels, which are transported to the site and welded on site. At this point, however, the tube is not under pressure, so it deforms into an oval shape, which makes welding more difficult because the sheets will no longer line up.

Also, for example when used as an oil or gas pipeline, the pipeline is usually buried. When the pipe is under pressure, it readily supports the external loads imposed by the roadbed. However, this pressure varies and may even become a negative pressure relative to the outside. There is then a great risk of deformation of the tube.

Consequently, the cross-sectional area of the tubes formed by welding metal tube elements is relatively limited, usually less than ^2m2 .

Through several years of research, the present inventor has invented a new manufacturing method for pipelines for conveying pressurized fluids, which does not have the above-mentioned disadvantages.

In this method, the pipeline consists of a sealed thin-walled tube, usually a metal tube, fixed on a rigid support, usually made of reinforced concrete or preloaded concrete. In this way, the metal pipe makes the system airtight and withstands the internal pressure, the thin walls are only subjected to tensile stresses, and the concrete body makes the pipe rigid, while it is supported on the laying surface by a wider surface, which makes the applied load Dispersed and better able to withstand local subsidence.

In the method disclosed in document EP0767881, the concrete support preferably consists of three parts, a horizontal base supported on the ground and two lateral support parts forming vertical feet along the sides of the pipe. Thus, the assembly is in the shape of a U that surrounds the entire bottom of the tube. In this way, the tube consists of four plates in cross-section, a bottom plate on the base, two side plates on the side legs respectively and a side plate connected to the corresponding ends of the side plates. Cut the attached top plate. Said side panels are supported by the two legs of the support so that their opposite sides are well positioned for welding.

Such ducts are easily fabricated from prefabricated elements of a length that can be adapted to transport and handling capabilities.

The inventors have carried out further research in order to simplify the method of manufacture of the pipe, in particular to make the prefabricated parts lighter and easier to install, while maintaining the advantages of the prior art.

Accordingly, the present invention generally relates to fluid communication conduits comprising a sealed tube mounted on a rigid support forming a base resting on a laying surface, said tube having a longitudinal axis and defined by a thin barrier wall Formed, the thin barrier wall closes on itself to form a sealed tubular housing comprising an upper part and a lower part to be fitted on the inner surface of said support body.

According to the invention, the support comprises a single-piece part on both sides of the housing, which is L-shaped in cross-section, comprising a substantially vertical branch and a substantially horizontal branch, the vertical branches forming the support body. Lateral flaps extending along respective sides of the lower part of the tube, the horizontal branches extending below said lower part of the tube and forming at least part of the base of the support resting on the laying surface.

It is particularly preferred that, at least over a certain length of the tube, the side wings and the base of the support body form a U-shaped single piece.

According to another embodiment of the invention, at least over a certain length of the tube, the support comprises two parts of L-shaped profile, the horizontal branches of which are connected on both sides of the tube median plane passing through the longitudinal axis, so that Form a continuous base.

Usually, the support body is made of reinforced concrete and can be conventionally reinforced to support the applied loads, especially loads that will be spread to the side parts. However, according to another preferred characteristic of the invention, the reinforcement may be made of at least one curved sheet inserted into the concrete support and having two branches, one horizontal and one vertical, both of which extend into the corresponding branch of each L-shaped portion of the support.

Preferably, in order to ensure continuity of load transmission, each L-shaped lateral portion of the support includes an inner surface for laying and mounting the casing, the direction of the inner surface gradually changing between a substantially horizontal bottom and a substantially vertical top. Variety.

Other preferred features are the subject of the dependent claims.

The present invention may be better understood from the following description of specific embodiments, which, for purposes of illustration, are represented by the accompanying drawings.

Figure 1 is a schematic transverse perspective cross-sectional view of a portion of the conduit of the present invention.

Figure 2 schematically shows the deformation of the pipe when the pressure is reduced relative to the outside.

Figure 3 shows another embodiment.

Fig. 4 is a detailed view of a side portion of a support body.

Fig. 5 is a cross-sectional view of another embodiment.

Figure 6 is a detailed view of the device for connecting the pipe and the support.

Figure 7 schematically shows the formation and transport of the preform.

Figure 8 shows another embodiment with interconnected beams.

Figures 9 and 10 show an embodiment in which the direction of the duct axis can be changed.

FIG. 1 is a schematic perspective view of a portion of a pipeline according to the invention, generally comprising a pipe A connected to a concrete support B. FIG. The tube A consists of curved metal plates welded together along adjacent sides, the number of plates being dependent on the required channel cross-section. For a channel section approximately 2 meters wide, the tube A may comprise only two plates, respectively a bottom plate 1 constituting the lower part of the tubular housing and a top plate 2 constituting the upper part, said plates 1, 2 along their longitudinally adjacent sides 11, 21, 11', 21' welding. The length L covered by each plate 0, 2 in the direction of the longitudinal axis 0, 0' of the pipe depends on the conveying capacity. The plates 1a, 1b, 2a, 2b of the two successive sections of the tube are welded along their opposite transverse sides 12a, 12b, 22a, 22b in order to constitute a sealed tubular casing A subject to the internal pressure.

This tubular casing A is laid on a support B which surrounds the entire bottom of the tubular casing, thus being U-shaped, comprising a base 3 and two lateral wings 31, 31', the lateral wings 31, 31' rise vertically along the two sides of the housing A. The assembly is symmetrical with respect to a vertical central plane P1 passing through the longitudinal axis 0,0'.

The wings 31, 31' of the base B extend upwards substantially to the level of the horizontal diameter plane P2 of the tube passing through the axes 0, 0', even slightly above this plane in the embodiment shown in Fig. 1 .

The sides 13, 13' of the bottom plate 1 of the casing A can also be higher than the plane P2, since they are reinforced by the two wings 31, 31' of the base, so that their longitudinal sides 11, 11' remain parallel and aligned with the existing The corresponding edges of the pipe sections are aligned, which facilitates the installation and welding of the top plate 2 . In this way, the fan-shaped angle covered by the bottom plate 1 is greater than 180°, forming a concave angle, while the top plate 2 covers the fan-shaped portion of the remaining angles.

The upper part of the tube 1 is composed of the top plate 2 and the side walls 13, 13' of the bottom plate 1. The side walls 13, 13' of the bottom plate 1 are connected tangentially to the top plate 2. The shape of the upper part of the tube 1 is preferably centered on the 0, 0' axis A sector of the rotating cylinder of , at least down to the diameter plane P2. Therefore, the casing A can withstand the applied load in an optimal state. In fact, the applied internal pressure merely determines the tensile load of the metal wall, which is easy to calculate and whose thickness is relatively small. It should be noted that the semi-circular walls 2, 13, 13' make it optimal to withstand internal pressure and external loads, for example, when the pipes are buried under the foundation and before the fluid under pressure is added to the housing A The state is subjected to internal pressure and external loads.

The lower part 1 is not semicircular and may even be flat, since the base 3 of the concrete support B and the support reinforcements need to be adapted to withstand bending stresses.

In the embodiment described in the inventor's prior patent application EP0767861, the support body consists of three parts, a base extending below the bottom of the housing and two lateral supports supporting the side walls of the housing part, the two lateral bearing parts are pressed against the side surfaces of the base by means of preloaded tie rods.

In this arrangement, the joint between the two lateral bearing parts of the support body and the base is hinged.

On the contrary, in the present invention, the side portion 31 of the support body B at least on both sides of the housing A is constituted by a single-piece portion whose cross-section is an L-shaped section comprising a substantially vertical The vertical branch 32 extends along the corresponding side wall of the housing A, and a substantially horizontal branch 33 extends below the tube and constitutes at least a part of the base 3 supported on the ground.

Such a design can ensure the continuity of load transmission, so that the transmitted stress exerted by the side walls 13, 13' of the shell A on the two wings 32, 32' of the support body B is absorbed by the base 3 of the support body .

In this way, it is possible to dispense with preloaded tie rods, which in prior art embodiments are fastened in the base, whereby the prior art base would be subjected to high compressive stresses. In the present invention, the base is only subjected to bending stresses due to the tendency of the side walls 32, 32'

Thus, the base 3 of the support can be made lighter, and even for pipes of very large cross-section, for example about 3 meters in diameter, a one-piece support can be formed, as shown in FIG. 1 .

Typically, the support body B comprises reinforced concrete, as shown in partial section in FIG. 1 . The reinforcement 5 must be in a suitable U-shape and may generally comprise longitudinal reinforcing steel bars 51 connected to transverse reinforcements 52 .

The radius of curvature of the bottom surface 14 of the tubular housing may be larger than that of the top surface 2, and may even be flat. However, the substantially horizontal bottom surface 14 and the substantially vertical side walls 13, 13' of the plate 1 bear against the inner surface 38 of the L-shaped portion 31 of the support body B, preferably between the vertical branch 32 and the horizontal branch 33 There is a gradual transition zone in order to ensure the continuity of the stress propagation without any corners.

For example, Fig. 2 schematically shows a pipeline according to the invention comprising a metal pipe A connected to a concrete base B in solid lines, and shows in mixed lines when the outside of the pipeline has an overshoot relative to the inside of the pipeline, for example under the pressure of the weight of the roadbed. Deformation A', B' determined by calculation at high pressure.

Obviously, the scale of the deformation has been exaggerated for better visibility, but it will be appreciated that due to the propagating stresses applied to the wings 32, 32' of the concrete support B are continuously propagated to the base of the concrete support B 3, 33, 33', so that the concrete support B is gradually deformed, so that the two wings 32, 32' make the tubular shell rigid at the side walls 13, 13' of said shell, and in contact with the concrete support There is no risk of rupture at the part where B is connected.

Due to the good distribution of stresses throughout the volume of the monolithic concrete support B, the mass of said support can be significantly reduced compared to prior art embodiments.

In order to make the structure lighter, it is preferable to use "high performance concrete", whose compression and tension bearing capacity is far greater than that of ordinary concrete, for example exceeding 40Mpa. Such bearing capacity enhances the interconnection and fit between the metal pipe A and the concrete support B. On the other hand, the performance of concrete can be enhanced by the use of high bearing capacity steel bars. In this way, the thickness of the metal wall can be reduced, and therefore the overall weight of the element can also be reduced.

And, as shown in Figures 3 and 4, angle irons 7, 7' can be used to strengthen the connection between the metal wall A and the support body B, each angle iron 7, 7' forms at least one angle, and one side 71 of the angle covers Surrounding the upper surface 30' of each wing 32, 32' of the support body B, the other side 72 extends upwardly and is tangent to the outer surface of the corresponding side wall 13, 13' of the thin wall A at the opening of the support body B. One side 71 is enclosed in concrete, the other side 72 is welded to the outer surface of the side walls 13, 13', thus making it reinforced and supported on the wings 32, 32' of the support body B, thereby avoiding, for example, Water ingress hazard.

The angle irons 7, 7' are provided with a closed portion 73 which preferably covers the outer edge of the upper surface 30' of the support B in order to reduce the risk of concrete cracking.

Preferably, the angle irons 7, 7' extend along the entire surface 30' of the support body B, but they may also comprise simple closed joints spaced at a distance from each other.

According to another particularly preferred feature, the continuous propagation of stresses within the support body B simplifies the formation of the reinforcement, as shown in FIGS. 3 and 4 .

In this case, the reinforcement may in fact consist essentially of a simple sheet 54 bent with the same curvature as the wall 1 of the casing A and the inner surface 38 of the support B, said sheet 54 being embedded in the concrete 30 . Holes 55 are provided over the entire surface of the sheets 54 to ensure penetration of the concrete for better interconnection. Furthermore, as shown in FIG. 4, the sheets 54 may also have protrusions 56 on both surfaces thereof for complete interconnection.

Two parallel thin plates 1 and 54 are connected by concrete 30 and bonded together to form a curved beam absorbing the propagated stresses of the side walls 32, 32'.

In order to prevent cracking, it is sufficient to place a lighter reinforcement 5' such as welded wire mesh at the corners of the support B, especially along the outer surface of the support.

As shown in Figure 4, due to the simplification of the reinforcement, there can be free space at each corner of the support body, in which a butt pipe 58 can be placed, which can be included in the support body B, and Longitudinal spaces are formed for the passage of eg cables, conduits or longitudinal preload rods.

According to another preferred feature, as shown in FIG. 4 , the concrete 30 may be fiber reinforced concrete, which, as is well known, comprises a large number of metal fibers 57 regularly distributed and randomly oriented within the concrete support. In this way, the concrete support body B can be made lighter.

Usually, fiber reinforced concrete will use small fillers in order to be able to distribute the metal fibers 57 randomly, the larger parts being actually smaller than 8mm. Also, additives are often used to enhance flow, especially for high-performance concrete. Thus, during casting, such concrete can easily flow into the reinforcement so that vibrations are generally not required.

According to another preferred feature of the present invention, in order to ensure the interlocking of the concrete body and the metal sheet A, a corrugated connection can be installed on the outer surface of the metal sheet A, the corrugated connection is preferably made of longitudinal iron bars 81 and The metal wire mesh 8 of transverse iron bars 82 constitutes. This wire web is commercially available and may be corrugated, for example by passing it between rollers with shingled grooves, the corrugations being parallel to the longitudinal iron bars 81 . Such a corrugated wire mesh is easily deformed in the transverse direction and can therefore be attached to the outer surface portion 14 of the shell A to which the concrete body is attached. The top 83 of this corrugation can be electro-welded in a known manner on the outer surface 14 of the wall 1 , which forms a lost mould, as shown in FIG. 6 . When adopting the concrete of small particle, especially adopting high-performance fiber-reinforced concrete, concrete can infiltrate in the part 84 of the barbed wire that extends between top 83, like this, this barbed wire is buried in the concrete entirely, after the concrete hardens, in the A good interlock is formed between shell A and concrete body B. As shown in FIG. 6, on the upper part of the concrete body B, the connection can also be strengthened by an extension 85 of a wire mesh 8 having a suitable shape. In this way, the risk of water penetration between the casing A and the concrete body B can be avoided and the aforementioned angle iron 7 can be omitted.

Moreover, due to the use of fiber-reinforced concrete, the aforementioned other reinforcements 52, 54 can be omitted. This feature also enhances the toughness of the structure.

Thanks to the invention, both the formation of the prefabricated elements and the implementation of their construction into pipes can be simplified.

Even for very large dimensions, the bottom 1 of the tubular casing A may consist of a thin sheet which is pressed or rolled in order to obtain the desired radius of curvature. As shown in Fig. 7, to make the preform of the pipe, the plate 1 is turned over and placed on the bottom of the mold 6 to constitute a lost mold. This plate 1 is preformed on the outer arch side with interconnections 53, for example welded profiles as shown in FIG. 6 or means for connecting the tubes to the support. After the side walls 61 of the mold and the reinforcement 5 are installed, concrete is poured to the desired height so that the base B has the desired thickness.

It should be understood that the sheet-shaped reinforcements in Figures 3 and 4 can be pre-installed on the panel 1 at the desired distance.

After solidification, the assembly was removed from the mold and turned over.

In order to handle the preform thus formed, it is obvious that the preform must have anchorage points on the upper part of the wings 32, 32', such as rings 40 enclosed in concrete, so that the slings can hook it. If desired, this ring 40 can also be welded on the angle iron 7 closed on the upper surface 30' of the support body B.

Such prefabricated elements can be easily transported to the construction site, for example by trailer 62, as shown in FIG. 6 . In this way, very large prefabricated parts can also be transported by road, as long as the height h of the prefabricated part plus the height of the trailer still complies with the regulations of the road. In fact, it suffices to specify the length L of the prefabricated part in such a way that the prefabricated part is placed transversely on the trailer and generally does not exceed the permissible width.

The top plate 2 of the tube is made of curved sheets which can be simply stacked for transport to the site.

To form the duct, after preparing the mounting surface C, place the prefabricated elements one after the other along the longitudinal axis 0, 0' while adjusting the height and position so that the prefabricated element B1 to be installed is aligned with the already installed prefabricated element B The side edges 11a, 11b of the plates 1a, 1b are aligned with each other so that the corresponding transverse edges 12a, 12b are in contact with each other.

The top plate 2a can then be installed and the assembly can be welded along the longitudinal joints 11, 21 and the transverse joints 12, 22, respectively.

At each longitudinal end of the preform, the concrete support B terminates and is slightly recessed from the sheet 1, so as to leave a space 34 between two adjacent pieces B1, B2, allowing the installation of the preform and the welding of the sheet easier. The longitudinal reinforcements 51 have auxiliary parts which intersect each other in the spaces 34 and are then embedded in the sealing mortar.

Thus, the formation of the duct is very easy, since the elements can be prefabricated in the factory and then transported to the construction site.

However, for very large dimensions, it is also possible to form the element in situ. In fact, the sheets 1, 2 can be formed in the workshop and sent to the site stacked on a trailer, it only needs to cooperate with the required mold 6, so the mold is particularly simple. For larger pipes, the element can be fabricated in mobile prefabrication plants close to the site.

Obviously, if the support B can be made lighter, this must be calculated relative to the environment in which it will be used. For example, when the pipe is in the groundwater table, the concrete support preferably acts as a counterweight so that its mass can be determined.

However, the invention is obviously not restricted to the details presented in the above examples, since other embodiments are possible without departing from the scope defined by the claims.

For example, in order to make the supporting body lighter, it is possible, as shown in FIG. stress, the base 3 mainly makes the housing rigid, especially during assembly, and it distributes the load over a larger surface. However, the overall height H of the element will increase, so in the case of large channel cross-sections the embodiment generally with a flat base as shown in FIG. 1 is preferred.

Furthermore, according to Fig. 7, the tubular shell construction in two parts is especially advantageous for pipes with very large cross-sections, but, due to the advantages provided, the invention can also be used for pipes of normal size, for example with a diameter of 0.5 m pipeline. At this time, it is preferable to use the closed tube directly.

For example, it is known in the art to bias roll a large length of sheet and weld adjacent roll sides to form a tubular closure shell which is then cut into small pieces , whose length is adapted to the handling and conveying capacity.

Such a tubular piece can be placed between the two side walls of a mold with two seats on each side of the tube, the bases being placed at a sufficient height, for example to the middle of the tube. Interlocking elements such as corrugated wire mesh 8 are then mounted on the raised portion of the upper portion of the tube. Concrete can then be poured into the mold thus constructed to a height higher than the upper portion of the pipe, as previously described, so that the concrete body has a defined thickness.

On the other hand, although the use of a U-shaped one-piece concrete support is particularly advantageous, it is also possible, as shown in FIG. Connected at plane P1. The casing is then constructed so as to leave a free space 37 between the opposing faces of the two branches 33, 33', in which free space 37 the auxiliary reinforcements in the two elements cross each other and cooperate with the longitudinal reinforcements , and then, embed the assembly in sealing mortar to make the base continuous.

In addition, the height of the longitudinal joints 11, 21 can vary, as can the height (h') of the side walls 32, 32', but the side walls 32, 32' must be of sufficient height so as to be lower in relation to the external environment. The sidewalls 13, 13' remain rigid during compression and withstand the extrusion stress of the pipe.

Obviously, the concrete support body B must be strong enough to withstand the handling, delivery and installation of the prefabricated parts. In fact, due to the interlocking between the metal wall A and the concrete body B, the rigidity of the whole is enhanced. However, in order to make the supporting body B as light as possible, sometimes it can be reinforced by connecting beams installed on the upper ends of the two wing plates 32, 32', so that the following parts have rigidity during handling. The support beam is detachably mounted so that it can be removed after the lower parts have been installed, so that the top plate 2 can be installed. However, the connecting beam is still beneficial after the piping has been constructed. In fact, as shown in FIG. 8 , it can form a support 41 of a mechanically welded structure spanning the pipe, the inner shape 42 of which corresponds to that of the upper wall 2 . The bracket 41 can also be pre-installed on the top plate 2 when the supporting body B is sufficient to withstand the handling operation. The brackets 41 provide external protection and reinforce the panel 2, which can be reduced in thickness which can be calculated only by the tensile load due to the internal pressure. In this way, the plate 2 , reinforced by one or several brackets 41 , is better able to withstand crushing when the pipe is depressurized with respect to the external environment.

The pipe of the present invention has other advantages as well.

For example, in curved sections of pipes, adjacent concrete pieces can be connected to each other in order to prevent the pipes from slipping. As shown in FIG. 9, the preforms are easily formed in such a way that the transverse joint plane Q, in which the transverse edges 12, 22 of the casing A lie, is inclined relative to the longitudinal center plane P1 of the respective preforms so as to enable a gradual change of direction. Adjacent elements are then interconnected by preloaded tie rods 43 preferably inserted in tubes 58 shown in FIG. 4 , the ends of which bear against bosses 35 outside the ends of the respective elements B1 , B2 .

Similarly, as shown in FIG. 9 , the joint plane Q may also be inclined with respect to the horizontal axis, so as to accommodate variations in the inclination of the laying surface C .

As shown in FIG. 6, as mentioned above, in order to ensure the interlock between the concrete body B and the pipe A, it is preferable to install on the pipe A a corrugated wire mesh 8, which is cheap and can be easily formed. However, such perforated panels, permeable to concrete and corrugated, can also be obtained in other ways, for example: by forming a grid with grids, or by tearing the sheet into blades to obtain caillebotis.

Moreover, it is clear that the characteristics and properties of the walls making up the pipe A must be suitable for the fluids conveyed and the pressures to which they are subjected.

It should be noted that the special construction of the pipe allows for a reduced wall thickness compared to ordinary metal pipes. In this way, the tube can be made of a specific metal, such as stainless steel, in which case the increased cost can be compensated by eliminating the lining normally required to improve the flow regime.

At this time, it is more preferable to improve the interlocking between the pipe and the concrete by a corrugated wire mesh as shown in FIG. 6 .

In the claims, the reference signs inserted after the mentioned technical features are only for easier understanding, and are by no means limiting the scope thereof.

Claims (20)

1. A pipeline for the communication of fluids, comprising a closed pipe (A) mounted on a rigid support (B) forming a a base (3), said tube having a longitudinal axis and consisting of a thin barrier wall which closes on itself to form a closed tubular casing comprising an upper part and a lower part (1), the lower part (1) attached to and mounted on the inner surface (38) of the support (B), Wherein, the support body (B) comprises a one-piece part (31, 31') on each side of the longitudinal axis (0, 0') of the tubular casing (A), the one-piece part (31, 31') L-shaped in cross-section, comprising a substantially vertical branch (32) and a substantially horizontal branch (33), the vertical branch (32) extends along the respective sides of the lower part of the pipe (A), and the horizontal branch (33) is at The underside of the lower part of the tube (A) extends and forms at least a part of the base (3) of the support (B) resting on the ground (C). 2. Pipe according to claim 1, wherein the support (B) is cast in a single piece at least over a certain length, and the horizontal branches (33, 33 ') meet to form the base (3) of the support (B). 3. Pipe according to claim 1, wherein: at least over a certain length, the support (B) consists of two L-shaped parts (36, 36') with horizontal branches (33, 33'), which Opposite ends are connected to each other at a central plane (P1) of the housing (A) passing through the longitudinal axis (0, 0') so as to form a continuous base. 4. Pipeline according to any one of the preceding claims, wherein the support body (B) is made of reinforced concrete. 5. Pipe according to any one of the preceding claims, wherein each L-shaped portion (31) of the support body (B) includes an inner surface (38) for application and installation of the housing, the direction of the inner surface being substantially horizontal Gradual change between the bottom of the and a more or less vertical top. 6. Pipeline according to claim 5, wherein: the inner surface (38) of the two branches (32, 33) of each L-shaped part (31) has the same radius of curvature as the corresponding part of the tubular shell (A), the curvature The radius changes continuously without any corner points. 7. Pipe according to any one of the preceding claims, wherein each vertical branch (32, 32') of the support body (B) is at least partly covered by a metal piece (7, 7') forming at least one such A concave corner, one side (71) of the concave corner is covered on the upper surface (30') of the branch (32, 32') of the support body (B), and the other side (72) is at the opening of the support body (B) with the The side walls (13, 13') of the housing (A) are tangential and welded to the side walls (13, 13'). 8. A pipe as claimed in any one of the preceding claims, wherein the support body is made of reinforced fiber concrete. 9. The pipeline according to claim 1, wherein: the supporting body (B) is made of high-performance concrete, and the compressive capacity of the high-performance concrete exceeds 40Mpa. 10. Pipe according to any one of the preceding claims, wherein: at least in each L-shaped section (31, 31'), the support body (B) is made of concrete with reinforcements (52), the reinforcements (52) Embedded in concrete (30) and has two branches, a horizontal branch and a vertical branch, each extending in a corresponding branch (32, 33) of the L-shaped part (31) of the support body (B). 11. Pipeline according to any one of the preceding claims, wherein the support body (B) consists of concrete with reinforcements comprising at least one curved sheet (53) embedded in the concrete (30) and substantially in line with The lower part ( 1 ) of the housing (A) is parallel, said thin plate ( 53 ) goes upwards into the vertical branches ( 32 , 32 ′) of the support (B). 12. Pipeline according to any one of the preceding claims, wherein: there are also a plurality of spaced apart brackets (41) distributed along the pipeline and having a surrounding upper part (2) of the tubular casing (A) inner surface (42). 13. The pipeline according to any one of the preceding claims, wherein: the pipeline comprises adjacent prefabricated parts, each prefabricated part extends on a certain length of the pipeline, each prefabricated part comprises a pipe unit (A), and the pipe unit (A ) form a tubular shell closed in section, and a part of its outer surface (14) forms the lost mold (lostcasing) for the molded concrete body B unit. 14. Pipeline according to claim 13, wherein: each pipe unit (A) consists of at least two bent metal sheets, respectively a bottom plate (1) with two longitudinal parallel sides (11, 11') and at least one top plate (2), the top plate (2) has two sides (21, 21'), which are welded to the longitudinal sides (11, 11') of the plate, and the concrete body (B) It is molded on a part of the plate (1) between the longitudinal sides (11, 11'). 15. Pipeline according to one of claims 13, 14, wherein each pipe unit (A) is interlocked with the support body unit (B) by means of a connecting piece consisting of a perforated metal plate (8), The metal plate (8) is formed with corrugations and attached to the molded part (14) of the outer surface (14) of the pipe unit (A), said corrugations having a crest (83) welded to said outer surface and a protruding portion (84) between two adjacent tops, the support body unit (B) consists of concrete cast on said molded portion (14) and penetrating into said corrugations so that Fully bury the perforated plate (8). 16. Pipe according to claim 15, wherein the perforated plate (8) is a wire mesh plate comprising longitudinal straight strips (81) parallel to the longitudinal axis of the pipe (A) and transverse corrugated strips (82). 17. Pipe according to claim 15, wherein the perforated plate is a metal grid formed with corrugations parallel to the longitudinal axis of the pipe (A). 18. Pipe according to claim 14, wherein at least two consecutive elements (B1, B2) terminate at their adjacent ends in transverse connections inclined relative to the axis (0, 0') of the pipe (A) plane (Q) in order to change the direction of the pipe axis (0, 0'). 19. A method of manufacturing a pipe consisting of prefabricated parts according to claims 14 to 18, wherein: for each element, at least two thin plates are preformed with a predetermined radius of curvature, and the two thin plates are respectively the bottom plate (1) and the top plate (2 ), the raised interconnecting pieces (53, 8) are welded to the outer surface of the bottom plate (1), the plate (1) is placed on the bottom of the mold (6), and the raised outer surface is turned upwards, the The required reinforcements are installed, the concrete is poured until its height slightly exceeds the top height of the overturned slab, it is removed after the concrete has hardened, and the pipe unit thus prefabricated is turned over, and the top slab (2) is welded to the slab (1 ) to close the duct, the preforms thus formed are placed on the laying surface and connected to form the duct. 20. 13. A method of manufacturing a pipe formed from a preform as claimed in claim 13, wherein the metal pipe is formed continuously by bias rolling a sheet having a substantial length and welding adjacent seam edges To form a closed tube, said tube is cut into tubular pieces, the length of this tubular piece is adapted to the ability of handling and delivery, interconnecting pieces (53, 8) are welded in the molded part (14) of each tubular piece , the tubular member is placed in a mold (6) having two side walls (61) parallel to the longitudinal axis of the tubular member by turning the molding part (14) upwards, and in The sides of the tubular member extend upwards, and the side walls (61) of the mold (6) are connected to the wall of the tube (A) by means of a flat plate forming a bottom at an intermediate height defining the sides of the support height, then concrete is poured into the mold thus formed until its height slightly exceeds the top height of the molded part (14), after the concrete has set, it is removed, the thus prefabricated unit is turned over, and it can be placed onto the laying surface to form the pipeline.

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