METHOD AND KIT FOR FILLING A SCOUR CAVITY

Abstract

METHOD AND KIT FOR FILLING A SCOUR CAVITY The invention relates to a filling kit and a method for filling a scour cavity (13), said method comprising: arranging first hollow filling elements (15) having a first diameter in the scour cavity (13), then arranging second hollow filling elements (16) having a second diameter greater than the first diameter, in the scour cavity (13), and also assembling a plurality of wall elements (18) for closing the scour cavity (13) and containing the hollow filling elements (15, 16) in the scour cavity (13). Figure for abstract: Figure 4

Description

Title of the invention: METHOD AND KIT FOR FILLING A SCOUR CAVITY Technical field of the invention

[0001] The invention relates to a method for filling a scour cavity. More particularly, the invention relates to a filling method for stabilizing an infrastructure affected by scour having formed at least one scour cavity in a foundation of the infrastructure. The invention relates, for example, to a method for filling a scour cavity located in railway foundations, and more particularly the foundations of retaining walls and bridge abutments for railways. The invention also relates to a kit for filling a scour cavity. Technological background

[0002] During floods or floods, infrastructure foundations can be damaged by water currents. A water current can carry away part of the materials used for the foundations, by a scouring phenomenon. Such events can create scour cavities which destabilize / weaken the infrastructure and prevent normal use. Some foundations, such as retaining walls and abutments of railway bridges, are particularly sensitive to this phenomenon and to the formation of scour cavities. However, on a railway affected by scouring phenomena, traffic can be slowed down or even interrupted.

[0003] Scour cavities require rehabilitation to ensure the stability of the foundations and restore the service provided by the affected infrastructure, in particular to restore normal traffic on railway lines. However, during flooding events or major floods, this can represent a significant amount of work for technical teams. In addition, these rehabilitations require heavy equipment and materials that cannot always be brought close to the areas affected by the scour. Indeed, since the foundations of the infrastructure are weakened, in some cases, equipment and tool transport machines cannot use the infrastructure to bring the equipment and materials needed for its rehabilitation closer.

[0004] Furthermore, failure to intervene for an extended period following such an event may cause additional damage to the infrastructure. For example, a railway track whose foundations are weakened by scouring could deteriorate further, due to gravity or weather, if the scour cavities were not quickly filled. Repairs would then be longer and more expensive.

[0005] It is therefore necessary to implement temporary measures to limit these side effects but also to allow the use of the infrastructure to be restored and repair equipment and materials to be brought closer. Thus, such temporary measures can make it possible, in the context of a railway infrastructure, to restore train traffic on the track affected by the scour. Such temporary measures must also make it possible to bring machines closer to provide materials and tools for carrying out definitive work to fill the scour(s). Objectives of the invention

[0006] The invention aims to provide a filling method and a filling kit which allow a repair intervention to be carried out as a temporary measure on an infrastructure foundation.

[0007] The invention also aims to provide, in at least one embodiment, a method which can be implemented easily and without tools by human operators.

[0008] The invention also aims to provide, in at least one embodiment, a method which can be implemented quickly.

[0009] The invention also aims to provide, in at least one embodiment, a method which can be adapted to different types of situations.

[0010] The invention also aims to provide, in at least one embodiment, a method for obtaining a scour cavity filling with good compressive strength. Statement of the invention

[0011] To do this, the invention relates to a method for filling a scour cavity, said method comprising the steps of: a. arranging a plurality of first hollow backfill elements, the first hollow elements having a first average diameter, in the scour cavity, b. after step a), arranging a plurality of second hollow filling elements, the second hollow elements having a second average diameter greater than the first average diameter, in the scour cavity, c. assembling a plurality of wall elements so as to form a wall: • at least partially closing the scour cavity, and • adapted to be able to contain the first hollow filling elements and the second hollow filling elements in the scour cavity.

[0012] Throughout the text, reference is made to "hollow elements" or "hollow filling elements" without distinction of their specific dimensional characteristics, to describe characteristics applying to all hollow elements without distinction.

[0013] The hollow filling elements are hollow, that is to say that they contain within them an internal cavity. This closed internal cavity is empty of solid or liquid material. These closed internal cavities may comprise air or any other gas or mixture of gases.

[0014] The hollow elements are adapted to individually have a compressive strength suitable so that, once a method according to the invention has been implemented, the compressive strength of all the hollow elements arranged - and where appropriate leveled and / or compacted - in the cavity provides sufficient stability to the infrastructure to be able to be used, including under degraded operating conditions. More particularly in certain embodiments, the hollow elements are adapted to obtain a compressive strength close to the compressive strength of concrete.

[0015] Thus, in a method and a kit according to the invention, while offering a sufficiently high compressive strength to restore the use of an infrastructure, the elements being hollow, the latter remain sufficiently light, individually, to be easily transported and handled by hand by human operators, in particular in sites that are difficult to access or where access has been made impossible for machines by scouring. Human operators can handle the hollow elements without difficulty to arrange them by hand in the cavity. Thus, in a method according to the invention, a human operator places one or more hollow elements at a time in the scouring cavity, without the aid of a machine.

[0016] In step a), the first hollow elements are advantageously arranged in the cavity so as to form a first layer of hollow elements. Thus, by gravity, the first hollow elements form a first filling layer in the lower part of the cavity.

[0017] Similarly, in step b), following step a), the second hollow elements are advantageously arranged in the cavity so as to form a second layer of hollow elements. Thus, by gravity, the second hollow elements form a second filling layer in the cavity, said second layer being placed immediately above the first layer.

[0018] The inventors have determined that arranging successive layers of hollow elements of increasing average diameter from the lowest layer of the cavity to the highest layer of the cavity makes it possible to obtain a filling providing good stability of the infrastructure. The use of an infrastructure can thus be restored to provisionally and until the infrastructure is finally restored. In particular, a railway track infrastructure foundation that has been scoured may be restored provisionally so as to allow trains to run on the railway to restore service and / or to allow access to the affected area for heavy machinery capable of transporting tools and materials for the final restoration of the railway track foundations.

[0019] The wall is adapted to close an opening of the cavity, for example a lateral opening of the cavity. The wall makes it possible to prevent the hollow elements arranged in the cavity from escaping through an opening of the cavity. In addition, the wall makes it possible, where appropriate, to retain the hollow elements during a step of compacting the hollow elements in layers, said hollow elements coming at least partly to bear on said wall. Thus the wall forms a formwork wall for the hollow filling elements.

[0020] The wall may further be adapted to be watertight, so as to prevent the introduction of water into the scour cavity. Indeed, since scouring occurs in particular in flood zones, the presence of a watertight wall makes it possible to protect the foundations of the infrastructure against further scouring which could affect the stabilization obtained by stacking hollow elements by a method according to the invention. The wall also prevents hollow elements from being carried away by a water current.

[0021] The wall elements are advantageously assemblable together, for example by nesting by elastic deformation. Thus the wall elements can be assembled together by human operators without tools or with few tools.

[0022] The wall elements can also be easily disassembled, during a later step, to be able to be removed from the cavity, as well as the hollow elements, so as to allow a definitive restoration of the infrastructure.

[0023] In addition, the wall elements advantageously have dimensions and a low average density allowing them to be easily transported and handled by human operators without machines on the site of the scour cavity. Thus, the wall elements can be made of a low-density material such as a polymer material and / or can comprise hollow cavities.

[0024] Depending on the configuration and the access available to the scour cavity, step c) of assembling the wall elements can be carried out: - before filling the cavity, - as the cavity is filled, - after filling the cavity.

[0025] In some embodiments, in which the wall is assembled and put into place as the cavity is filled, a first portion of the wall is assembled before arranging hollow elements in the cavity, so as to contain these hollow elements; then, the level of the hollow elements introduced into the cavity being close to reaching or having reached the level of the first wall portion, new wall portions can be assembled before continuing to fill the cavity with additional hollow elements. Thus, in order, the method can for example comprise the steps of: - assembling a plurality of wall elements so as to form a first wall portion, - place the first hollow elements in the cavity, - assembling a plurality of wall elements so as to form a second assembled wall portion and a continuation of the first wall portion, - place the second hollow elements in the cavity.

[0026] Furthermore, a method according to the invention comprises, after step a), at least one step of leveling the first hollow elements in the scour cavity.

[0027] Leveling may consist of simple leveling or may also include compaction of the hollow elements.

[0028] Thus the first hollow elements are distributed in a substantially homogeneous manner in the first layer. The compressive strength of the first layer is optimized and generally homogeneous.

[0029] Leveling can be carried out after having arranged all of the first hollow elements in the cavity or at regular intervals after having arranged a determined thickness of first hollow elements.

[0030] Similarly, the method may comprise, after step b), a step of leveling the second hollow filling elements in the cavity.

[0031] Generally, during or after each step of filling the scour cavity with hollow elements, the method may comprise a step of leveling and / or compacting the hollow elements.

[0032] The second average diameter is greater than or equal to twice the first average diameter.

[0033] More particularly, the second average diameter may be approximately three times greater than the first average diameter.

[0034] The inventors have determined that such average diameter ratios make it possible to obtain a stable and compression-resistant filling.

[0035] In some embodiments, all of the first hollow members have the same average diameter. The first hollow members may also all have the same shape.

[0036] Similarly, all the second hollow elements may have the same shape and / or the same average diameter, and / or all the third hollow elements may have the same shape and / or the same average diameter, and / or all the fourth hollow elements may have the same shape and / or the same average diameter, etc.

[0037] The first average diameter of the first hollow filling elements can be chosen between one centimeter and 2.5 centimeters, for example of the order of 1.3 centimeters.

[0038] The second average diameter of the second hollow filling elements can be chosen between 3 centimeters and 5 centimeters, for example of the order of 4 centimeters.

[0039] A method according to the invention further comprises a step subsequent to step b), consisting of: arranging, in the scour cavity, a plurality of third hollow filling elements, the third hollow elements having a third average diameter greater than the second average diameter.

[0040] This step makes it possible to form a third layer formed of third hollow elements above the second layer of hollow elements.

[0041] The third average diameter may be greater than or equal to 1.5 times the second average diameter, for example approximately 1.9 times greater than the second average diameter.

[0042] The third average diameter of the third hollow filling elements can be chosen between 6 centimeters and 8.5 centimeters, for example of the order of 7.5 centimeters.

[0043] Furthermore, a method according to the invention may comprise a step consisting of: arranging, in the scour cavity, a plurality of fourth hollow filling elements, the fourth hollow elements having a fourth average diameter greater than the third average diameter.

[0044] The fourth average diameter of the fourth hollow filling elements can be chosen between 8 centimeters and 12 centimeters, for example of the order of 9 centimeters.

[0045] The fourth hollow elements are arranged in a fourth layer in the scour cavity after the third hollow elements have been arranged therein as a third filling layer. Before arranging the fourth hollow elements on the third layer of hollow elements, the method may comprise a step of leveling and / or compacting the third hollow elements.

[0046] In a method according to the invention, other successive layers with hollow elements of increasing average diameter can be produced. Thus, a fifth layer with hollow elements of a diameter of the order of 15 centimeters can be produced. Similarly, a sixth layer with hollow elements of a diameter of the order of 20 centimeters can be produced.

[0047] The hollow elements are quasi-spherical.

[0048] More particularly, in certain embodiments, the hollow filling elements may be spheres of determined diameter.

[0049] However, nothing prevents the hollow filling elements from having a different shape, for example they can have a regular or irregular polyhedral shape. Throughout the text the term "mean diameter" is used to define the average external diameter of a hollow filling element, as a representation of its average size when it has an irregular shape, in particular a non-spherical shape.

[0050] A method according to the invention further comprises a step of preparing the hollow elements comprising at least one step of assembling constituent parts of said hollow elements.

[0051] The preparation of the hollow elements may in particular comprise the assembly of half-shells adapted to be assembled together to form hollow elements. More particularly, two half-shells (in certain embodiments of the half-spheres) may be assembled two by two to form a hollow element. The preparation of the hollow elements may be carried out on site, close to the cavity, before being placed therein. In particular, the assembly of the hollow elements may be carried out by hand by one or more human operators.

[0052] Thus, the transport of such hollow elements can be optimized by stacking the half-shells together, so as to occupy less volume than hollow elements. Similarly, the manufacture of hollow elements is simplified, the manufacture of half-shells being simpler than the manufacture of hollow elements.

[0053] A method according to the invention further comprises a step of transporting hollow elements of different diameters - or assemblable parts making it possible to form the hollow elements - and wall elements to the site affected by the scour. This transport can be carried out by means of transport operated by humans or by autonomous vehicles.

[0054] A method according to the invention further comprises a step of additive manufacturing of the hollow elements.

[0055] The hollow elements can be manufactured directly in this form by additive manufacturing. Any additive manufacturing technique can be envisaged within the scope of the invention.

[0056] Similarly, in certain embodiments, the half-shells adapted to be assembled into hollow elements can be obtained by additive manufacturing.

[0057] A method according to the invention further comprises a prior step of purging the scour cavity.

[0058] Before arranging hollow elements therein, in a method according to the invention, the cavity is purged, that is to say cleaned of any foreign body which could hinder the arrangement of the hollow elements and the final stability of the filling of the cavity obtained by a method according to the invention. Thus, following the formation of scour by a flood or a flood for example, mud or floating foreign bodies which could have accumulated there are evacuated from the cavity.

[0059] A method according to the invention further comprises a step of arranging the first hollow elements among the second hollow elements.

[0060] More generally, a method according to the invention may comprise one or more steps consisting of arranging hollow elements of a determined dimension among hollow elements of larger dimensions. In particular, first hollow elements may be arranged among third hollow elements. First hollow elements may be arranged in the second layer, and / or in the third layer, and / or in the fourth layer, etc.

[0061] By extension, second hollow elements may also - alone or in combination with the first hollow elements - be arranged among third hollow elements, fourth hollow elements, etc.

[0062] Hollow elements of smaller dimensions than hollow elements of larger dimensions can thus be placed in interstices between hollow elements of larger dimensions. Indeed, the larger the average diameter of the hollow elements, the larger the interstices left free between these hollow elements. Thus, arranging hollow elements of smaller dimensions among hollow elements of larger dimensions in the upper layers makes it possible to maximize the compactness of the filling of the cavity.

[0063] A method according to the invention may in particular comprise a step of mixing hollow elements of smaller dimensions in a layer of hollow elements of larger dimensions.

[0064] The invention extends to a kit for filling a scour cavity, said kit comprising: • a plurality of first hollow filling elements, the first hollow elements having a first average diameter, • a plurality of second hollow filling elements, the second hollow elements having a second average diameter greater than the first average diameter, • a plurality of wall elements adapted to be assembled to form a wall: • capable of closing at least part of the scour cavity, and • adapted to contain the first hollow filling elements and the second hollow filling elements in the scour cavity.

[0065] The kit is suitable for implementing a method according to the invention.

[0066] The first average diameter is adapted to allow the introduction of the first hollow elements in the cavity. Similarly, the second average diameter is suitable for allow the introduction of the second hollow elements into the cavity.

[0067] The invention also relates to a method and a kit characterized in combination by all or part of the characteristics mentioned above or below. List of figures

[0068] Other aims, characteristics and advantages of the invention will appear on reading the following description given solely for non-limiting purposes and which refers to the appended figures in which: • [Fig.l], [Fig.2], [Fig.3] and [Fig.4] are schematic views representing different stages of the implementation of a method according to an embodiment of the invention, • [Fig.5] is a schematic view of a filling kit according to one embodiment of the invention.

[0069] Detailed description of an embodiment of the invention

[0070] In the figures, the scales and proportions are not strictly respected, for the purposes of illustration and clarity.

[0071] Identical, similar or analogous elements are designated by the same references in all the figures.

[0072] Figures 1 to 4 represent a cross-sectional view of a railway track 10 comprising a foundation 11 and an infrastructure of the engineering structure 12. This track has undergone scouring having created an scour cavity 13.

[0073] In [Fig.l], a first step of a method according to the invention has been implemented: the scour cavity 13 has been purged of any undesirable foreign element that the flood or inundation could have deposited there while withdrawing, such as for example driftwood, plastic residues, mud, etc.

[0074] Figures 2 to 4 show in detail the portion of the track affected by scour 13.

[0075] In [Fig. 2], other steps of a method according to the invention have been implemented.

[0076] In a second step, wall elements 18 in the form of assemblable blocks have been assembled together and arranged on an open side of the scour cavity 13 so as to close the lower part of said scour cavity 13. The wall elements 18 are advantageously light so that they can be transported and put in place by hand by human operators. For example, they can be made of light materials such as synthetic materials. Alternatively or in combination, the wall elements 18 can be at least partially hollow.

[0077] Then, in a third step, a plurality of first hollow filling elements 15 were arranged in the bottom of the cavity so as to form a first filling layer. In this embodiment, the first hollow elements 15 are spherical and have a diameter of approximately 1.3 cm.

[0078] The first hollow elements 15 may have been leveled and / or compacted to obtain a compact filling layer.

[0079] In [Fig.3], additional steps of a method according to the invention have been implemented.

[0080] In a fourth step, wall elements 18 were assembled to the wall elements 18 already put in place during the previous steps, so as to increase the height of the wall formed.

[0081] In a fifth step, a plurality of second hollow filling elements 16 were arranged in the cavity, on the first layer of hollow elements 15, so as to form a second layer of hollow elements 16. In this embodiment, the second hollow elements 16 are spherical and have a diameter of approximately 4 cm.

[0082] The second hollow elements 16 may have been leveled and / or compacted to obtain a compact filling layer.

[0083] In [Fig.4], additional steps of a method according to the invention have been implemented.

[0084] In a sixth step, new wall elements 18 were assembled to the wall elements 18 already put in place during the previous steps, so as to increase the height of the wall formed.

[0085] In a seventh step, a plurality of third hollow filling elements 17 were arranged in the cavity, on the second layer of hollow elements 16, so as to form a third layer of hollow elements 17. In this embodiment, the third hollow elements 17 are spherical and have a diameter of approximately 7.5 cm.

[0086] During this seventh step, first hollow elements 15 were deliberately mixed among the third hollow elements 17. This makes it possible to fill interstices of a smaller size than the third hollow elements 17.

[0087] The third hollow elements 17 mixed with the first hollow elements 15 may have been leveled and / or compacted to obtain a compact filling layer.

[0088] The wall formed by the plurality of wall elements 18 forms a retaining wall for the hollow elements 15, 16, 17 arranged in the scour cavity 13. The wall can also protect the hollow elements 15, 16, 17, and the cavity 13 from a new flood.

[0089] It can be seen in [Fig.4] that the scour cavity 13 has been filled and that the filling layers are contained by the wall. Thus the foundation is temporarily restored, so as to allow the circulation of trains and machines on the rails 12

[0090] [Fig.5] schematically shows a filling kit according to the invention. The kit comprises: a plurality of first hollow elements 15, a plurality of second hollow elements 16, a first plurality of half-shells 19 adapted to be able, by assembly two by two, to form third hollow elements, a second plurality of half-shells 20 adapted to be able, by assembly two by two, to form fourth hollow elements, a plurality of wall elements 18.

[0091] In this kit, the larger hollow elements are provided in the form of hemispherical half-shells, so as to limit their volume during transport. They are assembled at or near the excavation site by operators to form hollow elements for implementing a method according to the invention. The half-shells can be assembled by various means, for example by elastic deformation assembly.

[0092] The first plurality of half-shells 19 makes it possible to assemble spherical hollow elements with a diameter of 7.5 cm. The second plurality of half-shells 20 makes it possible to assemble spherical hollow elements with a diameter of 9 cm.

[0093] In this kit, the smallest hollow elements are supplied ready for use, in order to save the labor time which would be required for their assembly; especially since, the elements being smaller, their necessary number is also greater.

[0094] As described in the method, the first hollow elements 15 may be spherical with a diameter of 1.3 cm and the second hollow elements 16 may be spherical with a diameter of 4 cm.

[0095] The hollow elements 15, 16, 17, 19 are, like the wall elements 18, easily transportable and manipulated by human operators. Like the wall elements 18, the hollow elements 15, 16, 17, 19 can be made of synthetic materials. Thus, the elements of a kit according to the invention for implementing a method according to the invention allow easy intervention for the temporary restoration of an infrastructure foundation, even when machines cannot be approached to the site affected by the scour.

Claims

Claims

1. A method of filling a scour cavity (13), said method comprising the steps of: a. arranging a plurality of first hollow filling elements (15), the first hollow elements (15) having a first average diameter, in the scour cavity (13), b. after step a), arranging a plurality of second hollow filling elements (16), the second hollow elements (16) having a second average diameter greater than the first average diameter, in the scour cavity (13), c. assembling a plurality of wall elements (18) so as to form a wall: • at least partially closing the scour cavity (13), and • adapted to be able to contain the first hollow filling elements (15) and the second hollow filling elements (16) in the scour cavity (13).

2. Filling method according to claim 1, characterized in that it further comprises, after step a), at least one step of leveling the first hollow elements (15) in the scour cavity (13).

3. Filling method according to one of claims 1 or 2, characterized in that the second average diameter is greater than or equal to twice the first average diameter.

4. Filling method according to one of claims 1 to 3, characterized in that it further comprises a step subsequent to step b), consisting of: arranging, in the scour cavity (13), a plurality of third hollow filling elements (17), the third hollow elements (17) having a third average diameter greater than the second average diameter.

5. Filling method according to one of claims 1 to 4, characterized in that the hollow elements (15, 16, 17) are quasi-spherical.

6. Filling method according to one of claims 1 to 5, characterized in that it further comprises a step of preparing the hollow elements (15, 16, 17) comprising at least one step of assembling constituent parts of said hollow elements (15, 16, 17).

7. Filling method according to one of claims 1 to 6, characterized in that it further comprises a step of additive manufacturing of the hollow elements (15, 16, 17).

8. Filling method according to one of claims 1 to 7, characterized in that it further comprises a prior step of purging the scour cavity (13).

9. Filling method according to one of claims 1 to 8, characterized in that it further comprises a step consisting of arranging the first hollow elements (15) among the second hollow elements (16).

10. Kit for filling a scour cavity (13), said kit comprising: • a plurality of first hollow filling elements (15), the first hollow elements (15) having a first average diameter, • a plurality of second hollow filling elements (16), the second hollow elements (16) having a second average diameter greater than the first average diameter, • a plurality of wall elements (18) adapted to be assembled to form a wall: • capable of at least partially closing the scour cavity (13), and • adapted to contain the first hollow filling elements (15) and the second hollow filling elements (16) in the scour cavity (13).

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