STRUCTURE FOR ABSORBING IMPACT ENERGY

Abstract

The structure for absorbing impact energy comprises a core having a first surface exposed to impacts, and reinforcements which are distributed inside the core and have frictional interfaces with the core material. The reinforcements comprise first reinforcements that are positioned in a first reinforced region adjacent to the first surface and have main directions of resistance forming an angle of less than 45° with the first surface.

Claims

1. A structure for absorbing impact energy, comprising: an embankment having a first face exposed to impacts; and reinforcements distributed within the embankment and having frictional interfaces with the material of the embankment, wherein the reinforcements comprise first reinforcements placed in a first reinforced region adjacent to the first face and having main strength directions forming an angle of less than 45° with the first face.

2. The structure as claimed in claim 1, wherein the main strength directions of the first reinforcements are parallel to the first face of the embankment.

3. The structure as claimed in claim 1, wherein the embankment has a second face opposite the first face, and wherein the reinforcements comprise second reinforcements placed in a second reinforced region adjacent to the second face and having main strength directions forming an angle of less than 45° with the second face.

4. The structure as claimed in claim 3, wherein the main strength directions of the second reinforcements are parallel to the second face of the embankment.

5. The structure as claimed in claim 1, wherein the reinforcements are disposed horizontally.

6. The structure as claimed in claim 1, wherein the first face of the embankment is covered with a facing.

7. The structure as claimed in also having secondary reinforcements disposed transversely to the first face.

8. The structure as claimed in claim 1, wherein the first reinforcements comprise metallic reinforcements.

9. The structure as claimed in claim 1, wherein the first reinforcements comprise reinforcements made of polymer material.

10. The structure as claimed in claim 1, wherein the reinforcements comprise reinforcements of the geogrid or geotextile type.

11. The structure as claimed in claim 1, wherein at least some of the first reinforcements are arranged in successive segments along their main strength direction, with zones of mutual overlap between the segments.

12. The structure as claimed in claim 11, wherein embankment material is between the successive segments of a first reinforcement, in the overlap zones.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Other characteristics, details and advantages of the invention will become apparent upon reading the detailed description below, and upon analyzing the appended drawings, in which:

[0031] FIG. 1 is a cross-sectional side view of a structure according to one embodiment of the invention;

[0032] FIG. 2 is a cross-sectional side view of a structure according to another embodiment of the invention;

[0033] FIG. 3 is a cross-sectional side view of a structure according to another embodiment of the invention;

[0034] FIG. 4 is a cross-sectional side view of a structure according to another embodiment of the invention;

[0035] FIG. 5 is a cross-sectional front view of the structure, the cross section being on the plane V-V indicated in any one of FIGS. 1 to 4;

[0036] FIG. 6 is a cross-sectional top view of a structure according to the embodiment of the invention in FIG. 3;

[0037] FIG. 7 is a cross-sectional top view of a structure according to another embodiment of the invention;

[0038] FIG. 8 is a view similar to that of FIG. 6 after an energy impact.

DESCRIPTION OF THE EMBODIMENTS

[0039] The structure for absorbing impact energy described below by way of example takes the form of a protective merlon used to intercept falling rocks that can weigh up to several hundred metric tons, for example close to mountain roads. Such falling rocks can carry energies in excess of 6 megajoules (MJ).

[0040] This protective merlon has a first face, or front face, 10 shown on the right in FIGS. 1 to 4 and a second face, or rear face, 20 shown on the left. These faces 10, 20 can be substantially parallel as in FIGS. 1 and 3. The rear face 20 can also be inclined relative to the front face 10, as in FIGS. 2 and 4.

[0041] The orientation of the rear face 20 in FIGS. 2 and 4 allows better dissipation of the mechanical energy in the ground but increases the footprint of the structure on the ground.

[0042] Although the front face 10 is depicted as vertical in FIGS. 1 to 4, it can also be inclined, in particular if increasing the stability of the structure, modifying the footprint on the ground or adapting to an impact trajectory that is anticipated to be oblique is required. Specifically, it is advantageous for the front face to be as far as possible perpendicular to the trajectory of the impact.

[0043] The merlon of the exemplary embodiment comprises an earthen embankment 15 delimited by the front and rear faces 10, 20, in which reinforcements 16 are disposed that have frictional interfaces with the material of the embankment. These reinforcements 16 are, for example, strips that are regularly distributed in the vertical direction and extend horizontally, parallel to the front face 10 and to the rear face 20, in a direction perpendicular to the section plane in FIGS. 1 to 4. This orientation makes it possible to preferentially distribute the mechanical energy of an impact laterally rather than in the thickness of the protective merlon.

[0044] The reinforcements 16 are disposed in the regions of the embankment 15 that are acted upon the most in the event of an impact of which the energy has to be absorbed. In embodiments according to FIGS. 1 and 2, the reinforcements 16 consist of first reinforcements 16 placed in a first reinforced region 12 adjacent to the front face 10. In those in FIGS. 3 and 4, in addition to the first reinforced region 12, a second reinforced region 22 is provided near the rear face 20. This second reinforced region 22 comprises second reinforcements 16. In general, the central region of the merlon will not be provided with reinforcements 16 parallel to the faces 10, 20, so as to allow deformation of the merlon in the event of impact, so as not to weaken it.

[0045] However, secondary reinforcements 18 disposed transversely to the faces 10, 20 can also be incorporated into the embankment 15, so as to consolidate the whole. The secondary reinforcements 18 can in particular connect the front and rear faces 10, 20.

[0046] The reinforcements 16 can be disposed over the entire width of the merlon. Advantageously, reinforcements 16 are used that are disposed in successive segments along their main strength direction so as to partially overlap as illustrated in FIG. 5. Each zone 25 of mutual overlap between two successive reinforcements 16 has embankment material such that the reinforcements 16 are not in contact with each other. Thus, in the event of an impact, the energy is transmitted from one segment to the next by friction and dissipated gradually while at the same time avoiding causing the reinforcements 16 to break. This can allow the merlon to withstand a plurality of consecutive impacts without requiring repair.

[0047] Ideally, the reinforcements 16 are disposed perfectly parallel to the front and rear faces as illustrated in FIG. 6, so as to distribute the mechanical energy as laterally as possible. However, for logistical reasons or in order to particularly reinforce certain portions of the merlon and/or to protect certain portions thereof, the reinforcements can have a slight angle (which has to remain less than 45°) and be somewhat sunken into the thickness of the structure, as shown in FIG. 7. They are nevertheless considered to be substantially parallel to the front face 10 and to the rear face 20 because their orientation remains predominantly lateral. The main strength directions of the reinforcements 16 form an angle of less than 45° with the face 10 and/or 20 of the embankment 15.

[0048] Similarly, the reinforcements 16 can vary in height and have a slight slope. It is desirable for this slope to remain shallow so as to distribute the energy as laterally as possible.

[0049] FIG. 8 is a depiction similar to FIG. 6 after it has received a powerful and localized impact on its front face 10 shown at the bottom of the figure. It can be seen that the energy was able to be properly dissipated laterally by virtue of the reinforcements 16. The reinforcements 16 did not break. They remain disposed in a configuration capable of damping other impacts.

[0050] The invention is not limited to the examples described above. It encompasses all the variants that a person skilled in the art can envision within the scope of protection desired.