EP0015352B1 - Supporting structure for industrial equipments, which can be used as floating barge and foundation, and process for implementing it - Google Patents

Abstract

1. A supporting structur (10) for industrial equipment (11), intended for use, on the one hand, as a barge carried for transportation on the high seas by a barge carrier, but capable of floating on calm seas for th loading onto and unloading from this barge carrier, and, on the other hand, as a foundation in the ground when the equipment is installed on its site of use, characterized in that it is of the type comprising a unit assembling of adjacent, hollow, open-bottom compartments (13), sealingly closed at their upper portion by a wall (16) which supports the industrial equipment (11), the said compartments being only partially immersed when the structure is used as a floating barge, and that at least some of the said compartments are provided of means (17) intended to allow the air contained in the said compartment to escape outside, in a predetermined and limited amount, when the said structure is used as a barge.

Description

The invention generally relates to a support structure for industrial equipment, which can be used on the one hand as a floating barge for transporting this industrial equipment from its place of manufacture to its site of use, and on the other hand foundation in the ground when these equipments are installed on their site of use.

It is already known in the current technique to mount industrial equipment on a load-bearing structure which can also serve as a barge for transport by sea. These known structures have various drawbacks: they must have significant rigidity and mechanical strength, because they must be able to navigate on the high seas and withstand very large constraints without being significantly deformed. This therefore results in a high weight and a large draft. As these structures must be stranded at the site of use of industrial equipment, their large weight and draft require major civil engineering work at the site of use. When these structures are buried in the ground to serve as a foundation, they are subject to significant corrosion. In addition, for transport at sea, they must be compartmentalized and equipped with ballast systems.

Examples of structures of this type are described in US Patent No. 3,262,411 relating to a barge made up of closed watertight compartments and American Patent No. 1,908,714 relating to a barge made up of open bottom compartments. Such a structure with open bottom compartments is also disclosed in publication no. 2,341,481 of French patent application no. 77 04839, but it is applied in this case to a crane carrier vessel comprising a platform supported by the columns hollow connected to submerged buoyancy hulls.

However, in none of the cited documents is a support structure for industrial equipment which can serve as a floating barge supported by a barge carrier on the high seas, in particular comprising means for adjusting the hydrostatic thrust as a function of the load supported. at the level of the various compartments constituting it.

The main object of the present invention is precisely to produce a support structure comprising such means.

It therefore offers a support structure for industrial equipment, intended to serve, on the one hand, as a barge carried, for transport on the high seas, by a barge carrier, but capable of floating in calm waters for safe loading and unloading of this barge holder, and, on the other hand, foundation in the ground when the equipment is installed on their site of use. The support structure according to the invention is characterized in that it is of the type comprising a unitary set of adjacent hollow compartments with open bottom, sealed in their upper part by a wall which supports said industrial equipment, said compartments n 'being only partially submerged when the structure is used as a floating barge. According to the invention, at least some of the compartments comprise means intended to allow the air contained in said compartments to escape outside, in a predetermined and limited quantity, when said structure is used as a barge.

• La figure 1 est une vue schématique en perspective d'une structure porteuse d'équipements industriels selon l'invention; la figure 2 est une vue partielle en perspective avec arrachement partiel de cette structure; la figure 3 est une vue en coupe longitudinale schématique d'une structure selon l'invention, servant de barge flottante; la figure 4 est une vue partielle schématique en coupe montrant la fixation d'un tube de réglage de poussée hydrostatique dans un compartiment d'une structure selon l'invention; la figure 5 représente schématiquement la division de cette structure en différentes zones correspondant à la répartition des charges sur ladite structure; et les figures 6 et 7 représentent schématiquement deux modes de fixation d'une charge sur la structure porteuse selon l'invention.

The invention will be better understood, and other objects, characteristics, details and advantages thereof will appear more clearly during the explanatory description which follows, made with reference to the appended schematic drawings, given solely by way of example illustrating an embodiment of the invention and in which:

• Figure 1 is a schematic perspective view of a supporting structure of industrial equipment according to the invention; Figure 2 is a partial perspective view with partial cutaway of this structure; Figure 3 is a schematic longitudinal sectional view of a structure according to the invention, serving as a floating barge; Figure 4 is a schematic partial sectional view showing the attachment of a hydrostatic thrust adjustment tube in a compartment of a structure according to the invention; FIG. 5 schematically represents the division of this structure into different zones corresponding to the distribution of the loads on said structure; and FIGS. 6 and 7 schematically represent two methods of fixing a load on the support structure according to the invention.

There is therefore shown diagrammatically in FIG. 1 a support structure according to the invention, generally designated by the reference 10, and the industrial equipment 11 that it supports on its upper face. By way of example, and to fix the ideas, it will be specified that the supporting structure 10 according to the invention has here a rectangular shape with a length of about a hundred meters, a width of about thirty meters, and a height of 1.5 to 2 meters.

As can be seen more clearly in FIG. 2, this structure 10 consists essentially of a network of horizontal rigid beams 12, which cross each other perpendicularly, and which define between them the rectangular compartments 13. These beams 12 have a cross section transverse substantially in inverted T, comprising a vertical core and a bottom sole 14.

They are advantageously provided with vertical stiffening lugs 15 integral with the webs of the beams 12.

The adjacent compartments 13, defined by the longitudinal and transverse beams 12, are sealed in their upper part by a thin plate 16 of suitable material, while their lower part or their bottom remains open.

The structure 10 thus formed is therefore of the cellular type, comprising a very large number of adjacent compartments 13, isolated from each other, closed in an elegant manner at their upper part by the thin plate 16 and which are open bottom. The upper plate 16 serves only as a sealing skin. To fix the ideas, it can be specified, by way of nonlimiting example, that the compartments 13 have dimensions of the order of 3 × 6 m, and that the upper thin plate 16 has a thickness of the order of 0.7 at 1 mm, when it is made of steel.

The structure 10 according to the invention therefore differs essentially from the structures known from the prior art in that it does not include a bottom and in that it has a much less weight for the same material. It can be generally accepted that the weights, and the cost prices, of a structure according to the invention and of a structure according to the prior art are in a ratio of 1: 4 or 1: 3.

In Figures 3 and 4, there is shown schematically the means used according to the invention for adjusting in the compartments 13, when the structure is used in floating barge, the hydrostatic thrust as a function of the load supported at the various compartments .

We know that, in theory, the hydrostatic thrust exerted on a compartmentalized or alveolar structure must be proportional to the load at each point of the structure. At the point where a maximum load is applied, the hydrostatic thrust must be maximum; in a place with no load, the hydrostatic thrust must be zero, and in a place with a medium load, the hydrostatic thrust must be average.

According to the present invention, the compartments 13 do not include a bottom, and the hydrostatic thrust in each compartment is adjusted, by allowing water to penetrate to a certain height inside these compartments. This characteristic of the invention is shown schematically in Figure 3. In this figure, the structure 10 is shown floating on a body of water. The compartments 13a, 13c, 13d and 13e are shown provided with means which make the interior of these compartments selectively communicate with the external atmosphere. These means consist of tubes 17 which pass tightly through the upper thin plate 16. Each of these tubes extends over a certain height inside the associated compartment 13, and this height is determined as a function of the load which is supported by the structure at the level of the compartment considered. It is in fact the height of the tube 17 inside a compartment 13 which determines the height up to which the water will be able to rise in this compartment when the structure is launched. Indeed, as long as the water level does not reach the lower end of the tube 17 in a compartment 13, the air contained in this compartment can escape outside through the tube 17. When the water reaches the end of the tube 17, the air contained in the compartment 13 can no longer escape to the outside. However, the water continues to rise very slightly in the compartment, due to the compressibility of the area, and it rises inside the tube 17 to the level of the free surface of the water around the structure 10 , according to the principle of communicating vessels.

It can be seen in FIG. 3 that the compartment 13b has no tube 17. This compartment is the one at which the load supported is the greatest. To balance this load, the hydrostatic thrust at compartment 13b must be maximum. Water therefore enters this compartment only because of the compressibility of the air which is enclosed therein. Conversely, the structure 10 does not support any load at the level of the compartment 13e, and for this reason, the associated tube 17 extends inside the compartment 13e over a height corresponding to the level of the external free surface of the water. The hydrostatic thrust is zero at the level of compartment 13e.

The compartments 13a, 13c and 13d correspond to locations where the supported load is at an intermediate value, the heights over which the tubes 17 extend inside these compartments being substantially proportional to the supported load.

It is understood of course that the representation of Figure 3 is schematic and illustrates only the principle of the invention. Indeed, the structure 10 includes a very large number of compartments 13, for example 140 in the example shown in Figure 5, and most of which must be provided with a tube 17 adjusted to an appropriate height. The height of the tubes 17 is determined beforehand as a function of the calculated load supported by the structure 10 at the level of the compartments. But it has been found that it was not necessary to adjust the height of the tubes 17 in the compartments 13 individually, and that it was enough to group the compartments into sub-assemblies in each of which the hydrostatic thrust is adjusted to a single value , that is to say that the tubes 17 of the compartments forming the same sub-assembly are adjusted to the same height, these compartments being able to communicate with each other.

FIG. 5 represents an example of the distribution of the 140 compartments into 13 sub-assemblies defined transversely at I, II, III, IV and V and longitudinally at A, B, C. The sub-assembly It does not include plon tubes geurs. On the other hand, your compartments 13 of the sub-assemblies A, D and C of the other groups I, III, IV and V are all equipped with a dip tube. In each sub-assembly, the tubes are adjusted to the same height, and this height varies from one sub-assembly to another depending on the load supported.

FIG. 4 schematically shows a method of fixing a dip tube 17 in a compartment 13.

The upper end of the tube 17 is welded to the upper face of the plate 16, as indicated in 18, and under the plate 16, the tube 17 is welded in two zones 19 on a vertical tab 15 of stiffening secured to a beam 12.

In FIGS. 6 and 7, two modes of "attachment of the industrial equipment to the structure 10 are shown diagrammatically.

An equipment 11 a, having a relatively low weight, is carried by two cradles 20 which are fixed directly on the upper face of the thin plate 16, as shown in FIG. 6.

Equipment 11 b, having a greater weight, is also carried by cradles 21 which are fixed on load distribution plates or flanges 22, themselves fixed on the upper face of the thin plate 16, advantageously at the level of the 12 beams or appropriate reinforcements. When the thin plate 16 is made of steel, the fixing is of course done by welding.

The structure 10 can be made of any suitable material. In a preferred embodiment, it will be made of steel, but it can also be made of concrete, fiberglass, or different materials (one part in concrete, the other in steel), etc.

This structure according to the invention is implemented in the following manner.

It is constructed and assembled in a suitable place, on the ground, the industrial equipment 11 being permanently fixed to the structure 10 for example as described in FIGS. 6 and 7. The tubes 17 are mounted in the compartments 13, for example as shown in Figure 4, extending in each compartment to an appropriate height depending on the load supported at the compartment. The structure 10 carrying the equipment 11 is then launched into a calm body of water. The different hydrostatic thrusts exerted at the level of the various compartments 13 or of the various subsets of compartments make it possible to avoid significant relative vertical deformations of the structure 10. The latter is then loaded onto a semi-submersible barge carrier, or on any other suitable navigation device, in a manner known per se, and is transported to the site of use, where it is unloaded from on the barge carrier or device or the like in a body of calm water, before to ultimately be stranded on the site of use.

The structure 10 is intended for example to be buried, and to constitute the foundations in the ground of the industrial equipment 11 that it supports. For this, the compartments 13 are advantageously filled with concrete or any other suitable material. Thus, even if the structure 10 is subjected to corrosion, its deterioration or disappearance will not be of great importance, the concrete poured into the compartments 13 itself constituting a foundation insensitive to corrosion.

Of course, the invention is in no way limited to the embodiment described and shown which has been given only by way of example. In particular, it includes all the means constituting technical equivalents of the means described as well as their combinations, if these are used within the framework of the claims which follow.

Claims (14)

1. A supporting structure (10) for industrial equipment (11), intended for use, on the one hand, as a barge carried for transportation on the high seas by a barge carrier, but capable of floating on calm seas for the loading onto and unloading from this barge carrier, and, on the other hand, as a foundation in the ground when the equipment is installed on its site of use, characterized in that it is of the type comprising a unit assembling of adjacent, hollow, open- bottom compartments (13), sealingly closed at their upper portion by a wall (16) which supports the industrial equipment (11), the said compartments being only partially immersed when the structure is used as a floating barge, and that at least some of the said compartments are provided of means (17) intended to allow the air contained in the said compartment to escape outside, in a predetermined and limited amount, when the said structure is used as a barge.

2. A structure according to claim 1, characterized in that the said compartments (13) are sealingly closed by a thin plate (16) at their upper portion.

3. A structure according to claim 1 or 2, characterized in that at least some of the compartments (13) are sealingly isolated from each other.

4. A structure according to one of claims 1 to 3, characterized in that, when it is used as a floating barge, at least some of the said compartments (13) are filled with water from their open bottom over a portion of their height depending on the load supported at the level of these compartments.

5. A structure according to one of the preceding claims, characterized in that it is constituted by a unit network of rigid means (12) crossing perpendicularly and thus defining the said compartments (13).

6. A structure according to claim 5, characterized in that the beams (12) extend horizontally at the same level and have a vertical web defining the vertical walls of the said compartments (13).

7. A structure according to claim 6, characterized in that the webs of the said beams (12) are reinforced by vertical stiffening ribs (15) connected to the said webs.

8. A structure according to one of the preceding claims, characterized in that the said means comprise a stationary tube (17) sealingly traversing the said thin plate (16) and extending within the compartment (13) over a predetermined height depending on the rated load supported at the level of the said compartment (13).

9. A structure according to claim 8, characterized in that the said tube (17) is welded within the compartment on a said vertical stiffening rib (15).

10. A structure according to one of claims 5 to 9, characterized in that the said beams (12) and the thin plate (16) are of metal, for example of steel.

11. A structure according to claim 10, characterized in that the said industrial equipment (11) is secured on cradles (20) or supporting means which are either directly welded to the said upper plate (16), or welded on a metal plate forming a load distributing base (22), itself welded on the said upper plate (16) at the level of the said beams (12) or of appropriate reinforcements.

12. A method for using the structure described in one of the preceding claims, characterized in that it consists, after constructing and assembling the structure (10) and the industrial equipment (11), in setting the said structure (10) afloat on calm water, in thereafter loading it onto a barge carrier or an appropriate navigational appliance, and in transporting it to the site of installation, in unloading the said structure (10) from the barge carrier or the appliance by floating it on calm water, in running it aground at the site of use, and possibly in filling with appropriate materials the compartments (13) to constitute the aforesaid foundation.

13. A method according to claim 12, characterized in that it consists, when the structure (10) is used as a floating barge on calm water, in counterbalancing, by the hydrostatic thrust in the said compartments (13), the load supported at the level of these compartments.

14. A method according to claim 13, characterized in that it consists in grouping the adjacent compartments (13) into a certain number of sub-assemblies in each of which the hydrostatic thrust is constant for each compartment, the compartments of a same subassembly possibly being adapted to communicate with one another.

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