A road crash barrier

Abstract

 A road crash barrier (1) is described and comprises a plurality of posts (3) which can be anchored to the roadway structure (2) by means of coach bolts (21) in a manner such as to be translatable under stress in order to absorb the energy of an impact of a vehicle by deformation and/or breakage of the coach bolts (21), in which a shock-absorber (20) is interposed between each post (3) and the respective coach bolt (21) and comprises an element which is fixed firmly to the post (3) and in which a slot (25), elongate in the direction of translation of the barrier (1), is formed; the coach bolt (21) extends through the slot (25) in order to clamp the shock-absorber element against a sliding surface (15) of the post (3) with a predetermined load.

Description

[0001] The subject of the present invention is a road crash barrier according to the preamble to the main claim, of the type which is arranged for preferred installation at a side edge, conforming to category H4b of standards EN 1317-1E2TB81 and TB11.

[0002] A barrier of the above-mentioned type formed in accordance with the prior art is normally constituted by a plurality of posts arranged at 3000 mm intervals and anchored mechanically to the roadway-support structure by means of metal ties. The posts are then connected to one another at the front by means of a plate 6200 mm long, and at the top by a connection element which also serves to prevent a vehicle turning over during an impact.

[0003] A first disadvantage of these known barriers is that the installation of the mechanical connection connecting the posts to the roadway structure is quite laborious and inefficient.

[0004] Another disadvantage is that the length of the plates makes the assembly of the barrier also inefficient and, moreover, permits low assembly tolerances so that it is necessary to use suitable non-standard details on bends and on humps.

[0005] The problem underlying the present invention is that of providing a road crash barrier, particularly for installation at a side edge, which is designed structurally and functionally to overcome all of the disadvantages discussed with reference to the prior art mentioned.

[0006] This problem is solved by the invention by means of a barrier formed in accordance with the appended claims.

[0007] The characteristics and the advantages of the invention will become clearer from the detailed description of a preferred embodiment thereof, described by way of nonlimiting example, with reference to the appended drawings, in which:

• Figure 1 is a front elevational view of a road crash barrier formed in accordance with the present invention,
• Figure 2 is a side elevational view of the barrier of Figure 1,
• Figure 3 is an exploded, perspective view of the barrier of Figure 1,
• Figures 4 and 5 are views showing a detail of the barrier of Figure 1, in section and on an enlarged scale, in the normal condition, and in a condition of plastic deformation, respectively,
• Figures 6 and 7 are a plan view and a section taken in the plane VII-VII of Figure 6, respectively, of a detail of Figure 4.

[0008] In the drawings, a road barrier, generally indicated 1, is arranged at the side of a road structure of which a kerb 2, for example, made of concrete, is visible.

[0009] The barrier 1 comprises a plurality of posts, all indicated 3, on top of each of which a respective support 4 for a rail 5 of metal tubing is fixed. The rails 5 are joined end to end by means of sleeve couplings 6 to form a continuous structure and are housed in tubular structures 7 disposed on the free upper ends of the supports 4. At its opposite end, each support 4 carries a square flange mount 8 by which it is fixed to the post at a predetermined inclination to the vertical.

[0010] The posts 3 are made from sheet metal by bending and have two identical cheeks 9 joined together at the rear by a spine 10. At the front, the cheeks define a recess 11 for housing a reinforcement 12 with a U-shaped or tubular cross-section. A plate or skirt 13 is fitted on the cheeks, also at the front, and joins together a plurality of adjacent posts, generally three posts. With a preferred interaxial spacing or distance of 1500 mm between the posts, the skirt has a length of 3200 mm, a portion of which can overlap the adjacent skirt.

[0011] At the base, each post is completed by a sliding plate 14 on which a sliding surface 15 having a through-hole 16 is defined. The plate 14 has a lip 17 by means of which it is fixed to the front portion of the post 3 by a nut-and-bolt connection.

[0012] During the assembly of the barrier, the sliding plate 14 bears on the ground and is compressed between the surface of the kerb and a shock-absorber 20 by means of a coach bolt 21. The coach bolt 21 is arranged for chemical anchorage in a seat 23 disposed in the bottom of a recess 24 in the kerb 2, by means of a resin 22, for example, of the type which can be cross-linked by means of catalysts. The portion of the recess 24 between the seat 23 and the plate 14 is substantially enlarged in comparison with the stem of the coach bolt to permit the plastic deformation thereof which is shown in Figure 5, as a result of impacts which lead to relatively limited energy dissipation.

[0013] For impacts in which the energy involved is greater, the coach bolts are arranged to yield to breaking point, with a gradual yielding of the barrier which prevents the moving vehicle from riding over it. The coach bolt also extends through the hole 16 in the sliding plate 14 and through a slot 25 in the shock-absorber 20.

[0014] The shock-absorber 20 comprises a substantially inverted U-shaped element with a central portion 26 and two lateral flanges 27. The slot 25 is formed in the central portion 26 and the free edges of the two flanges 27 are urged against the sliding surface 15 of the plate 14 by the coach bolt 21. Vertical stiffening means are provided around the slot 25 and include an annular element 28 extending from the central portion 26 in the same direction and to the same extent as the flanges 27 so as to create further support for the U-shaped element on the plate 14.

[0015] At the rear, the posts are connected to one another by a strip 29 housed and fixed in a recessed seat 30 by bolted connection so as to be flush therewith. The strips do not therefore interfere with any subsequent fitting of coverings or rear buffer structures where required and are easy to handle, fit and galvanize.

[0016] The invention thus solves the problem posed, achieving many advantages over known road barriers. Amongst these is the fact that the provision for chemical anchorage of the coach bolts facilitates the fixing of the barrier to the roadway structure whilst maintaining its capacity for plastic deformation in the event of an impact by a vehicle.

[0017] Moreover, the use of a shorter distance between the posts permits a better distribution of the energy involved in the event of an impact, and permits the use of rails with smaller cross-sections, and of shorter skirt elements. The assembly of the barrier is thus facilitated and the need to use non-standard details on bends and humps is avoided.

Claims

1. A road crash barrier comprising a plurality of posts (3) which can be anchored to a roadway structure (2) by means of coach bolts (21) in a manner such as to be translatable under stress in order to absorb the energy of an impact of a vehicle by deformation and/or breakage of the coach bolts (21), characterized in that a shock-absorber is interposed between each of the posts (3) and the respective coach bolt (21) and comprises an element (20) which is fixed firmly to the post (3) and in which a slot (25), elongate in the direction of translation of the barrier (1), is formed, the coach bolt (21) extending through the slot (25) in order to clamp the shock-absorber element against a sliding surface (15) of the corresponding post (3) with a predetermined load.

2. A road barrier according to Claim 1 in which the shock-absorber element has vertical stiffening means (28) in the region of the slot (25).

3. A road barrier according to Claim 2 in which the stiffening means comprise an annular element (28) fixed firmly to the shock-absorber element, around the slot (25).

4. A road barrier according to any one of Claims 1, 2 and 3 in which the coach bolt (21) is arranged for chemical anchorage in a recess (24) in the roadway structure.

5. A road barrier according to Claim 4 in which the recess (24) is formed with a seat (23) for the fixing of an end portion of the corresponding coach bolt (21) and with an enlarged portion between the seat (23) and the shock-absorber element to permit plastic deformation of an intermediate portion of the coach bolt (21) under stress.

6. A road barrier according to one or more of the preceding claims in which the sliding surface (15) is defined on a sliding plate (14) associated with the base of the post (3) and translatable therewith.

7. A road barrier according to one or more of the preceding claims in which the posts (3) are provided at 1500 mm intervals.

8. A road barrier according to one or more of the preceding claims in which the shock-absorber (20) is formed with an inverted U-shaped cross-section and the slot (25) is formed in the central portion (26) of the U-shaped cross-section.

9. A road barrier according to one or more of the preceding claims in which the sliding plate (14) has a hole (16) through which the coach bolt (21) extends with clearance substantially equal to the enlarged portion of the seat (23).

Drawing