Impact protection system

Abstract

Disclosed is an impact protection system for road protection and embankments used along the roadway to prevent exits from roads or to absorb the impacts of a vehicle, or of a landslide or of boulders. The system has an improved impact absorbance within a reduced footprint. The system with a deformable coherent structure having a plurality of faces and a reinforced granular embankment; and also a set of integral reinforcers enveloping the deformable coherent structure and configured to distribute the energy of an impact over the deformable coherent structure. The set of integral reinforcers is configured such that a stress bulb generated by an impact with the deformable coherent structure is distributed over a plurality of faces of the deformable coherent structure, and the set of integral reinforcers has at least two ends connected by at least one linking element, and the at least one linking element passes through the deformable coherent structure. The set of integral reinforcers can entirely envelop the deformable coherent structure.

Description

[0001] IMPACT PROTECTION SYSTEM

[0002] The invention relates to the field of road protection and in particular to embankments used along the roadway to prevent vehicles from leaving the road or to absorb the impacts of a vehicle, a landslide or even rock blocks.

[0003] It is known to use a wide variety of massive structures to stop a localized or distributed impact.

[0004] Traditionally, protective berms are used and consist of a stack of individual containers such as bags or gabions, filled with heavy, usually granular material.

[0005] Other relevant solutions are described in the prior art, particularly in documents DE202006002393, EP3073017,

[0006] DE202013011453 and DE 201 12979.

[0007] Alternatively, it is known to use a reinforced embankment structure, equipped with facings that can be stiffened or vertical.

[0008] These structures make it possible to stop an impact either by dissipating internal energy, or through the inertia linked to the mobilization of a certain volume of the structure.

[0009] However, these massive structures generally have too large a footprint, which can be particularly problematic in confined spaces.

[0010] Structures with a smaller footprint are often highly slender, which limits their impact-absorbing capacity. Indeed, a block impacting this type of structure with significant energy is likely to penetrate it, causing a puncture, or at the very least, triggering external instability, such as the structure toppling or sliding.

[0011] Furthermore, known structures with limited footprints do not allow for sufficient internal energy dissipation due to their low deformability. Therefore, there is a need for a structure with a smaller footprint compared to known structures capable of absorbing comparable impacts. This problem can be formulated differently: there is also a need for a structure capable of absorbing a greater impact than known structures with a comparable footprint.

[0012] In this regard, the Applicant has succeeded in developing a new protection system which achieves this by engaging several faces of a deformable structure, and not just the face that suffers the impact.

[0013] The protection system according to the invention makes it possible in particular to protect roads in a confined context.

[0014] Therefore, a first object of the present invention consists of an impact protection system comprising:

[0015] a. a coherent deformable structure having several faces; and b. a set of interconnected reinforcements configured to distribute the energy of an impact on the coherent deformable structure,

[0016] in which the set of integral reinforcements is configured so that a stress bulb generated by an impact on the coherent structure is distributed over several faces of the structure, preferably over at least two opposite faces.

[0017] A coherent deformable structure is defined as a structure capable of absorbing mechanical energy, for example through internal energy dissipation. Advantageous examples of such structures include granular embankments, possibly reinforced with metallic or geosynthetic reinforcement.

[0018] Such structures can be easily adapted to the site's configuration. Ideally, these structures are chosen for their ease of assembly without the need for heavy formwork. They offer good durability, given their intended use, which is generally outdoors.

[0019] Ideally, structures are chosen so that they can be easily repaired if necessary. The fact that a structure has multiple faces does not necessarily mean that it is polyhedral.

[0020] Indeed, the concept of "face" in the context of the invention refers to an external surface of the structure that is susceptible to being directly subjected to a given type of impact. The type of impact is determined according to the intended use of the invention. Typically, the invention is designed to protect against impacts from vehicles, boulders, or landslides along the roadway. These constitute different types of impact.

[0021] The first face of the structure generally corresponds to the entire structure that is likely to be subjected to a direct impact of a given type. For example, in the case of a vehicle impact on a structure located at the edge of the road, this is the part of the structure likely to be struck by a vehicle that runs off the road without leaving the ground.

[0022] This face may have irregularities or raised features, but it will still be called a face for the purposes of this request. Faces are characterized by their propensity to undergo a direct impact of a given type or not.

[0023] At least one other face is not likely to be directly stressed by the impact likely to directly stress the first face.

[0024] The set of interlocking reinforcements comprises at least one reinforcement. If it comprises several reinforcements, it is sufficient that each reinforcement be attached to at least one other reinforcement in the set for the reinforcement set to be considered interlocking within the meaning of the invention.

[0025] The reinforcement assembly is configured so that at least a portion of the reinforcement assembly comes into tension under the effect of an impact on a face of the deformable structure and applies a compression increment to the deformable structure.

[0026] Thus, without the integrated reinforcement system, an impact would directly stress one face of the structure and generate a stress bulb from that single face. Thanks to the integrated reinforcement system, this same impact stresses not only the face it directly strikes, but also at least one other face indirectly. This allows the stress to be distributed by mobilizing a larger volume of the deformable structure, thereby increasing the inertia of the mobilized block. A portion of the stress generated by the impact can even be transmitted to the foundation soil when the integrated reinforcement system has at least one anchor point in the foundation soil.

[0027] Therefore, the same structure can absorb a greater stress for the same ground footprint, which constitutes a solution to the technical problem that the invention aimed to solve.

[0028] Preferably, the stress is distributed between two opposite faces: the set of interlocking reinforcements is, for example, anchored to the opposite face of the structure so that the impact causes tension in the reinforcement set, which transmits a stress to the opposite face. Distributing the impact over several faces generally applies a compressive increment to the deformable structure.

[0029] The set of integral reinforcements advantageously includes at least one element chosen from a net, a metallic element, a polymeric element, a bar, a cable, a woven or knitted textile, and preferably a metallic net.

[0030] The set of integral reinforcements may include elements passing through the deformable structure, for example, connecting elements distinct from non-passing reinforcements but adapted to transmit tension between different reinforcements through the deformable structure, or adapted to stress the structure internally in such a way as to further distribute the stress generated by an impact.

[0031] Compression transmission can be achieved through beams, slabs or other elements positioned at the top of the reinforcement assembly.

[0032] Advantageously, the set of integral reinforcements is arranged to completely enclose the coherent structure, which allows for stressing as many faces as possible for a given impact. The set of integral reinforcements is then preferably in tension. Advantageously, the set of integral reinforcements is pre-tensioned to improve its responsiveness under impact.

[0033] Advantageously, the system is configured to withstand energy exceeding 1 megajoule. Indeed, the system according to the invention is preferably used in a road context, and must therefore be able to absorb significant impacts.

[0034] Preferably, the coherent, deformable structure comprises reinforced granular fill. Reinforced granular fills offer very satisfactory mechanical properties considering their ease of production. Ease of production at a lower cost is particularly critical in road applications, as very long distances may need to be protected.

[0035] Granular backfill can be reinforced with metallic or geosynthetic reinforcement. This type of reinforcement is very effective in strengthening the properties of backfill when the structure is likely to be subjected to greater impacts, for example along high-speed roads.

[0036] The system of integral reinforcements preferably includes anchor points, with at least one anchor point located within the structural framework or within the foundation soil. Both anchor points could, for example, be located within the foundation soil. The location of the anchor points influences the tension within the system of integral reinforcements and thus how an impact will be distributed across the deformable structure.

[0037] The coherent structure can be fitted with a flexible facing, preferably a flexible facing selected from geosynthetic sheets and welded or woven wire mesh panels. The facing is then preferably separate from the integral reinforcement system. Alternatively, the integral reinforcement system can replace the facing of the deformable structure.

[0038] Preferably, the entire system of bonded reinforcements has a stiffness greater than 1.3MN / m. GEOBRUGG markets grid, sheet or net type reinforcements that have this type of characteristic.

[0039] Preferably, the set of integral reinforcements has at least two ends connected by at least one connecting element, preferably said at least one connecting element passing through the coherent structure.

[0040] Another object of the present invention consists of a method of constructing an impact protection system according to the invention comprising a first step of fully realizing a coherent deformable structure, and a second step of covering said coherent structure with a set of integral reinforcements configured to distribute the energy of an impact on the coherent deformable structure.

[0041] The construction is done sequentially, which is very advantageous because it allows the invention to be applied to pre-existing deformable structures.

[0042] Advantageously, the set of integral reinforcements can be pre-tensioned before a subsidiary step of anchoring the set of integral reinforcements in the structure and / or in a foundation soil.

[0043] A person skilled in the art will be able to adapt the invention to the specific constraints they will encounter. In particular, depending on the type of impact that the structure of the invention is intended to protect against, adjustments to the type of structure and the configuration of the integrated reinforcement system may be made without departing from the scope of the present invention.

[0044] The invention will be better understood with the aid of the non-limiting embodiment examples described below, and by examination of the accompanying drawing on which:

[0045] Figure 1 is a simplified representation of a first embodiment of the invention,

[0046] Figure 2 is a simplified representation of an alternative implementation of the embodiment of Figure 1; Figure 3 is a simplified representation of the embodiment of Figure 1 with an alternative anchoring system.

[0047] - Figure 4 is a simplified representation of the embodiment of Figure 1 with anchoring performed directly in the coherent structure,

[0048] - Figure 5 is a simplified representation of an alternative embodiment of the invention, and

[0049] - Figure 6 is a simplified representation of an alternative implementation of the embodiment of Figure 5.

[0050] In a first embodiment illustrated in figure 1, a massive structure 10 is provided, consisting of granular fill such as a reinforced soil, further comprising a vegetated facing, not shown.

[0051] This massive structure 10 has several faces. Although it is schematically represented as a rectangular parallelepiped in Figure 1, it can have other shapes. The structure is designed to be placed along a highway to absorb shocks caused, in particular, by potential vehicle accidents.

[0052] On a motorway, vehicles with a mass on the order of a tonne travel at a speed on the order of several tens of meters per second.

[0053] Crash test experiments allow us to estimate the duration of a collision, that is to say the time during which the body of a vehicle deforms, at about one tenth of a second.

[0054] In the event of going off the road, the corresponding deceleration is on the order of several hundred kilometers per square second.

[0055] The structure according to the invention must therefore be able to absorb an impact of several hundred thousand Newtons.

[0056] In order to distribute such an impact in the mass of the massive structure, the latter is wrapped with a metal net 1 1 put under tension by means of an anchor 12.

[0057] Thanks to this tensioned net, in the event of an impact, part of the force is absorbed by the net and transferred directly to other parts of the massive structure that would not have been affected without the net. The fact that the net is under tension limits the force absorbed by the net and allows a greater portion of the impact to be transmitted to other parts of the massive structure.

[0058] In the embodiment shown in Figure 1, the anchorage 12 is made at the level of the foundation ground, on either side of the massive structure 10.

[0059] However, anchoring 121 can also be carried out at the base of the structure, under the massive structure, as illustrated in Figure 3.

[0060] Alternatively, as illustrated in Figure 4, the anchorage 122 can be made directly into the solid structure. In this case, the anchorage must be sufficiently strong because the force of the impact will be transmitted largely through it.

[0061] The net 1 may consist of a two-dimensional network with a mesh shape, for example, rectangular, as illustrated in Figure 1, such as a metal grid. However, any network capable of transmitting force is suitable for implementing the invention. In particular, the net may consist of a one-dimensional network 111 oriented to connect two sets of anchors and to load several faces of the structure, as illustrated in Figure 2. The net then consists of linear sections that are disjointed and substantially parallel to each other, such as reinforcing strips. These strips are, for example, made of steel, or any suitable material.

[0062] The impact can also be transmitted via a complex structure 112 made up of several modules, for example, a first net 113 made of polymer material connected to a rigid slab 114, which is itself connected to a second net 115, as illustrated in Figures 5 and 6. The slab is, for example, a concrete slab, which may be integral with the solid structure. The first and second nets may or may not have identical grids, as illustrated. This grid may consist of a regular parallelepiped mesh, as in Figure 5, or a more irregular structure, for example, a linear structure stretched in a zigzag pattern between two edges of the solid structure, as illustrated in Figure 6. The choice of grid depends on the geometry of the solid structure, the availability of the materials used, and the most probable direction of an impact on the structure.

[0063] Indeed, since the structures according to the invention are, for example, intended to border a highway, they will be arranged over many kilometers so that the quantity of materials used can quickly become a limiting factor.

[0064] Furthermore, depending on the geometry of the massive structure and the direction of the impact, a particular network geometry will allow for a more or less effective distribution of the impact.

[0065] The two nets must be connected to the slab in such a way as to allow the transfer of the impact force from the first net to the slab and from the slab to the second net. For example, connecting means such as steel loops may be used.

[0066] The slab is preferably made of a material that is not likely to break when subjected to stress in the most probable direction of impact. This could, for example, be an oriented fiber material or anisotropic concrete. The slab can be designed to absorb part of the impact force, for example by deforming, whether in a plastic or elastic regime.

[0067] As illustrated in Figure 6, it is possible to provide an anchorage 122 passing under the massive structure and connecting the first and second nets so as to be able to stress the entire massive structure in compression.

[0068] The different embodiments illustrated are subject to a sequential installation.

[0069] In the case of the structures illustrated in Figures 3 and 6, the first step is to plan the anchoring methods located under the structure. The second step is to install the main structure.

[0070] In the case of the other structures illustrated in Figures 1, 2, 4, and 5, the process begins by designing the main structure. This may be a structure created specifically for this purpose or, alternatively, it may consist of pre-existing structures that need to be improved. In a final step, the structure is then covered by the net or the complex structure configured to distribute any potential impact on the main structure. The net is, for example, deployed from the crest of the main structure using specialized equipment.

[0071] It is understood that the embodiments described are not limiting and that it is possible to make improvements to the invention without going out of its scope.

[0072] Unless otherwise specified, the word "or" is equivalent to "and / or". Similarly, the word "a" is equivalent to "at least one" unless otherwise specified.

Claims

DEMANDS 1. Impact protection system comprising: a. a coherent deformable structure (10) having several faces; and b. a set of interconnected reinforcements (11) configured to distribute the energy of an impact on the coherent deformable structure (10), wherein the set of bonded reinforcements is configured so that a stress bulb generated by an impact on the coherent structure is distributed over several faces of the structure, preferably over at least two opposite faces, and wherein the coherent structure is provided with a flexible facing, preferably a flexible facing selected from geosynthetic sheets and welded or woven mesh panels.

2. Impact protection system according to claim 1, wherein the set of integral reinforcements (11) comprises at least one element selected from a net, a metallic element, a polymeric element, a bar, a cable, a woven or knitted textile, and preferably a metallic net.

3. Impact protection system according to one of the claims 1 or 2, in which the set of solidarity reinforcements is arranged so as to completely envelop the coherent structure.

4. Impact protection system according to any one of claims 1 to 3, wherein the system is configured to withstand an energy exceeding 1 megajoule 5. Impact protection system according to any one of claims 1 to 4, wherein the coherent deformable structure comprises a reinforced granular backfill.

6. Impact protection system according to claim 5, wherein the granular backfill is reinforced by metallic or geosynthetic reinforcements.

7. A protection system against impact according to any one of claims 6 to 7, wherein the set of integral reinforcements presents anchor points (12), and in which at least one anchor point (122) is housed in the coherent structure or at least one anchor point (12) is housed in a foundation soil.

8. Impact protection system according to any one of claims 1 to 7, wherein the assembly of integral reinforcements has a stiffness greater than 1.3 MN / m 9. Impact protection system according to any one of claims 1 to 8, wherein the set of integral reinforcements has at least two ends connected by at least one connecting element, preferably said at least one connecting element passing through the coherent structure.

10. Method of constructing an impact protection system according to any one of the preceding claims comprising a first step of fully realizing a coherent deformable structure, and a second step of covering said coherent structure with a set of integral reinforcements configured to distribute the energy of an impact on the coherent deformable structure.

11. Method according to claim 10, wherein the set of bonded reinforcements is pre-tensioned before a subsidiary step of anchoring the set of bonded reinforcements in the structure and / or in a foundation soil.