EP1624112B1

EP1624112B1 - Crash barrier element with deformable members between the element and the anchoring bolts

Info

Publication number: EP1624112B1
Application number: EP05076581A
Authority: EP
Inventors: Mauro Monteleone; Marcello Burzi
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-07-13
Filing date: 2005-07-11
Publication date: 2007-12-12
Anticipated expiration: 2025-07-11
Also published as: SI1624112T1; PT1624112E; ES2298927T3; DE602005003723D1; EP1624112A1; DE602005003723T2; PL1624112T3; ITRM20040347A1; ATE380903T1

Abstract

A New Jersey crash barrier element (1) is described, said element comprising a support base (2) fixed to the ground (T) by means of several anchoring bolts (3) which pass through holes formed therein, each of the said holes being an eyelet (5) oriented in a direction perpendicular to the element (1) and between the latter and each anchoring bolt (3) there being positioned transversely at least one compression-deformable member (4) having dimensions such that it is deformed, being shortened by a predefined length (L), when the barrier element (1) transmits to it a compressive force of predetermined intensity, allowing the barrier element (1) to be displaced in the direction of the said compressive force sliding over the said length (L) with respect to the anchoring bolt (3) along said eyelet (5).

Description

The present invention relates to the sector of crash barriers of the so-called New Jersey type and more specifically to the elements which, arranged as a continuation of each other, form these barriers, as disclosed in EP 1 136 624 A .
As is known, the main function of these barriers, and therefore the elements which form them, is to absorb as gradually as possible the stresses produced by the impact of a motor vehicle so as to keep it on the roadway, limiting the effects of the sudden decelerations affecting the occupants of this motor vehicle as a result of its impact against the barrier. The crash barrier elements designed hitherto essentially comprise a support base fixed to the ground by means of anchoring bolts which pass through it and the abovementioned cushioning effect is obtained by adjusting the tightening torque of the said bolts and forming the aforementioned holes in the manner of an eyelet so that, when an impact occurs, the element is able to slide over a given length with respect to the bolts which brake its movement owing to the friction which is generated between the underside of their fixing nut and the base of the said support base of the element.
This approach, however, has drawbacks, the most important of which consists in the objective difficulties which are encountered in obtaining the desired result.
It is sufficient in fact for the temperature and humidity conditions of the surrounding environment to change or for the abovementioned tightness setting not to be sufficiently precise in order to produce a substantial variation in the degree of the braking frictional force described above, adversely affecting or modifying considerably the impact cushioning effect which may vary considerably from that stipulated by the road safety regulations.
These regulations, as is known to persons skilled in the art, prescribe that a crash barrier element subject to an impact equivalent to the application thereon of a force of 9000 kg should move, sliding along the anchoring bolts, a distance of 10 cm.
Another drawback associated with the present-day constructional solutions described above consists in the greater cost resulting from the necessary operation of tightening the anchoring bolts by means of a torque spanner, which operation, moreover, sometimes is somewhat awkward to perform.
The inventors of the subject of the present application have therefore provided an innovative solution which eliminates all the drawbacks mentioned above, devising a New Jersey motorway barrier element in which a compression-deformable member is arranged transversely between each anchoring bolt and the said element, said member absorbing, by means of deformation, the stresses of an impact of given magnitude and allowing, with its deformation, a transverse displacement of the crash barrier over a predefined length.
Obviously the holes formed in the base of the element must be eyelets oriented perpendicularly with respect to the said element and having a sufficient longitudinal length to allow the abovementioned displacement over a predefined length.
In a barrier element according to the invention it is in fact no longer necessary to tighten the anchoring bolts with a predefined torque, but only by an amount sufficient to obtain the stability of the element, without producing friction between said bolts and the base and between the latter and the ground, as in the case of the elements designed in accordance with the state of the art.
The subject of the present invention therefore relates to a New Jersey crash barrier element as described in the accompanying Claim 1.
Two preferred examples of embodiment of the barrier element according to the invention will now be described, with reference also to the accompanying drawings in which:

Fig. 1 is a cross-sectional view of the first example of embodiment of a barrier element used as a central reservation;
Fig. 2 is the same cross-sectional view as Fig. 1 after the element has suffered a knock due to the impact of a motor vehicle;
Fig. 3 is a cross-sectional view of a second example of embodiment of a barrier element used along one side of the roadway;
Fig. 4 is an enlarged view of part of Fig. 3.

If we consider firstly Figure 1, this figure shows how, in an New Jersey barrier element 1 according to the invention, the support base 2 is fixed to the ground T by means of a plurality of anchoring bolts 3 (only one of which is visible in the drawing) which are fixed to the ground T using known methods and each of which penetrates inside said element upwards through an eyelet 5 oriented perpendicularly with respect to the barrier element 1.
Between the surrounding casing 7 of the latter and each anchoring bolt 3 there are arranged two members 4 which are compression-deformable, for example two metal plates which are folded as shown in the drawing and which are arranged symmetrically as an extension of each other in the transverse direction with respect to the element 1.
In the case shown, these two members 4 are integral with each other and form one piece, but could also be two parts which are separate from each other.
The assembly of the two members 4 is passed through by the shank of the bolt 3 via a complementary hole 6 formed therein.
When the barrier element 1 is subject to the thrust F (Fig. 2) resulting from the impact of a motor vehicle, the surrounding casing 7 transmits to one of the two members 4 (that arranged on the left-hand side in the case in question) a force which compresses it, deforming it firstly in a resilient manner and then in a permanent manner, causing it to crumple and shortening it by a length L. During the course of this deformation, the resilient member 4 absorbs and dissipates in a gradual manner the kinetic energy of the motor vehicle which caused the impact, and the barrier element 1 is displaced over a length L equal to the length of shortening of the member 4.
By suitably designing the members 4 both in terms of dimensions and in terms of type of material, it is possible to achieve the result that the element 1, following a thrust of given magnitude, is displaced over a given length L (for example, as already mentioned, equal to 10 cm for a thrust F of 9000 kg).
Obviously, the barrier element 1, during deformation of one of the members 4, may be displaced over the said length L since it slides with its base 2 relative to the anchoring bolts 3 by means of the already mentioned eyelet 5. In connection with the latter, it must be pointed out that, since a predefined friction between the base 2, bolts 3 and the ground T does not have to be produced, it may have a transverse width slightly greater than the diameter of the shank of the said bolts 3, and this play, which constitutes a further advantage of a barrier element according to the invention, is able to compensate for any errors in position of the anchoring bolts, facilitating and shortening the operations involved in installation of a crash barrier.
It must be pointed out that, in the case described hitherto, the surrounding casing 7 transmitted a compressive force to one of the members 4 by means of the projecting locators 8, but various different embodiments are possible using locators of a different type or kind, for example by forming them on the section which forms the said casing or another part of the barrier element (these further possible embodiments are not shown).
The example in Figs. 1 and 2 relates to a barrier element 1 with a symmetrical and mirror-image form relative to its vertical centre plane, to be used as a central reservation between two adjacent carriageways, but the barrier element of the invention may also be used, changing only its shape, as a lateral guard-rail.
An example of a barrier element 11 of this type is shown in Figures 3 and 4.
In these figures it is possible to see how the aforementioned barrier element 11 also has, as in the previous example, a support base 12 for resting on the ground T, provided with several eyelets 15 (one of which can be seen more clearly in Fig. 4) through each of which the shank of an anchoring bolt 3 penetrates, this bolt having the function of fixing the barrier element 11 to the ground T. Between the surrounding casing 17 of the element 11 and each bolt 3 there is also positioned in this case a compression-deformable member 14 arranged transversely with respect to the element 11. This member 14, which is realized for example in the form of shaped and folded metal plate as shown in the figures, performs the already described function of absorbing, by means of deformation and a reduction in its length, the kinetic energy associated with the impact of a motor vehicle against a crash barrier element, and, in a manner entirely similar to that illustrated in the previous example, it allows the barrier element 1 on which it is mounted to be displaced transversely, following an impact of given magnitude, over a predefined length.
In this case also, advantageously, the metal plate forming the compression-deformable member 14 has a hole which is passed through by the shank of the anchoring bolt 3, the fixing nut 19 of which ensures the connection between the bolt 3 itself and the said metallic plate.
It is pointed out how, in this case also, in order to transmit the force generated by the impact of the casing 17, the member 14 is provided with an angle-piece 18 which is fixed to the casing 17 in a suitable position, acts as a locating element and is in contact with the deformable member, but other solutions are also possible.
All the observations made in respect of the previous example are also applicable, without variation, to this second example of embodiment which, as in the case of the embodiment described first, enables the predefined object of the inventors to be achieved, namely that of providing a barrier element 1, 11 which, without the need for special tightening of its anchoring bolts, absorbs a predefined energy resulting from the impact of a motor vehicle, being displaced transversely over a length predefined during the design stage.

Claims

New Jersey crash barrier element (1, 11), comprising a support base (2, 12) fixed to the ground (T) by means of several anchoring bolts (3) which pass through holes formed therein, characterized in that each of the said holes is an eyelet (5, 15) oriented in a direction perpendicular to the element (1, 11) and between the element and each anchoring bolt (3) there is positioned, in transverse direction with respect to the element, at least one compression-deformable member (4, 14) having dimensions such that it is deformed, being shortened by a predefined length (L), when the barrier element (1, 11) transmits to it a compressive force of predetermined intensity resulting from impact, allowing the barrier element (1, 11) to be displaced in the direction of said compressive force sliding over the said length (L) with respect to the anchoring bolt (3) along said eyelet (5).
Barrier element (1) according to Claim 1, suitable for use as a central reservation, in which two of the said compression-deformable members (4) are positioned transversely between the element (1) and each anchoring bolt (3), integral or not with each other, being arranged as an extension of each other and on opposite sides of the anchoring bolt (3).
Barrier element according to one of the preceding claims, in which each of the said compression-deformable members consists of a resilient member (4, 14) having a through-hole (6, 16) inside which the shank of the anchoring bolt (3) is inserted in a complementary manner.