Shock energy dissipation traffic divider barrier

Abstract: This invention relates to a shock energy dissipation traffic divider barrier comprising a plurality of aligned energy dissipating members (1) supported on the bearing surface (2), each one of said dissipating members being supplied with a transverse guide for the passage of anchoring rope means (4) fastened at a point before the first dissipating member or the leading dissipating member, at a point behind the last one of said dissipating members (1), directly to the supporting surface of the dissipating members (1), so that such members can slide with respect to said rope members (4); said rope members (4) being provided with at least one predetermined-stretch device (6).

Description: This invention relates to a shock energy dissipating traffic divider barrier. More particularly, this invention relates to a barrier of the type mentioned above, that can be employed in the field pertaining to roads and/or to airports, for urban and extra-urban structures, said barrier providing a structure capable of ensuring an optimal dampening of impacts and of strongly reducing the cost of maintenance. At present, metal plate members are usually employed as traffic dividers, said members making up a reinforced barrier especially at places close to exit points. Such kind of barrier is realized through the overlapping of a number of plates and many uprights so as to obtain a sufficient size to realize the necessary stiffness and the necessary impact strength. However, their assembling has put into evidence the need for a remarkable maintenance that, in some cases, means even the need for the partial or total reconstruction of the whole structure. Another kind of traffic divider member that has been adopted consists of a rubber and metal plate end member. More particularly, it provides a number of plates with the interposition of rubber members (as for instance tires). Such devices, following to repeated impacts, require the total or partial reconstruction, so that the maintenance costs of the same are definitely high. A third type of traffic divider member adopted at the present time is made up of a light aerated concrete structure, which comprises a plurality of dovetail-shaped, series-connected members, which in case of impact are intended for a partial or total destruction so that, in some cases, fragments are found on the roadway. Accordingly, the Applicant intended to realize an impact energy dissipating traffic divider barrier capable of optimally supporting both front and side impacts without requiring a remarkable maintenance. These results are obtained together with other results, according to the present invention, by suggesting the realization of a traffic divider barrier made up of a sequence of cellular members which are generally of cylindrical or elliptical cross-section and are made up of rubber or of any other material having a suitable elastic modulus, said members resting on a basement member and being connected to the ground through a horizontal, predetermined-stretch anchoring device. In DE-U-8905428 it is described a shock energy dissipating traffic divider barrier according to the introducing portion of claim 1. Accordingly, the specific object of the present invention consists in a shock energy dissipating traffic divider barrier according to the characterizing portion of claim 1. According to a preferred embodiment of the barrier according to the present invention, a bearing member or shoulder is provided at a point behind the last one of said dissipating members, said bearing member being so shaped as to supply a supporting surface that perfectly couples to said dissipating member, said rope means that come out of said dissipating member being coupled to said bearing member or shoulder. More particularly, said dissipating members have a cellular or any other similar equivalent structure and they are cylindrical or elliptical in shape. Just for exemplification purposes, a height of 100 cm and a diameter of 120 cm can be reported for each one of said dissipating members. Moreover, they can be arranged by placing them directly on a reinforced concrete basement which has been realized as a completely separate member with respect to the already existing barrier. Preferably, said dissipating members are made up of rubber or of any other material having a suitable elastic modulus and deformability. More particularly, a material will be needed having an elastic modulus E of 20-80 kg/cm² and a SHORE hardness of 20-85 SH/A. The energy dissipating members of the barrier according to the present invention are arranged at a slight distance from one another, but in any case the last member will always rest on said suitably shaped bearing member. Preferably, a sequence of 3 or 4 energy dissipating members is provided. The sequence of said energy dissipating members aligned to form the barrier according to the present invention can be provided with a first or leading dissipating member and with a terminal dissipating member, both supplied with a guide for the passage of the anchoring rope means, said guide being arranged at a slope so as to allow the rope means anchored to the ground to enter and to exit at the height provided for their passage through the successive energy dissipating members, said sequence being also provided with one or more energy dissipating members including a horizontal guide for the passage of said rope means. According to another embodiment of the barrier of the present invention, each one of said energy dissipating members can be provided with a sloping guide and with a horizontal guide, which are arranged at right angles to one another, so that each member can be indifferently employed as the leading or first member and/or as the terminal member of the sequence, or not as the end member as well. Preferably, said horizontal guide is realized at a height of about 20 cm from the ground level. Preferably, said anchoring rope means are made up of a steel rope of suitable size. The predetermined-stretch device of said rope means can be arranged on said rope means themselves indifferently at the leading position and/or at an intermediate position and/or at the terminal position. According to the present invention, said predetermined stretch device is preferably arranged at the terminal portion of said rope means, at the point corresponding to the coupling with said bearing member, and said device consists of a steel spring that is compressively stressed. The present invention will be disclosed in the following according to some preferred embodiments of the same with particular reference to the figures of the enclosed drawings, wherein: Figure 1 is a perspective view of a kind of embodiment of the barrier according to the present invention; Figure 2 is a side view of the barrier shown in Figure 1; Figure 3 is a top view of the barrier shown in Figure 1; Figures 4a, 4b and 4c are three top views of the barrier according to the present invention, respectively in the rest position, after a front impact, and after a side impact; Figure 5 shows a cross-sectional view of an energy dissipating member of the barrier according to the present invention; and Figure 6 shows schematically a possible application of the barrier according to the present invention. The traffic divider barrier according to the present invention comprises, in the kind of embodiment shown in the drawings mentioned above, four energy dissipating members 1, of circular cross-section, which are made up of rubber. Said energy dissipating members 1 are supported on a reinforced concrete basement 2 which is completely independent of the already existing traffic divider 3. The anchoring of said energy dissipating members 1 to the ground is realized by means of a metallic rope 4 that passes through them along the diametrical direction at a height of about 20 cm. Said rope 4 is fastened at a point before the first of the dissipating members 1, i.e. at a point before the dissipating member that occurs frontally to the vehicle, directly to said basement 2. On the contrary, the rope 4 is coupled to a reinforced concrete shoulder 5 at the point corresponding to the last one of said dissipating members 1, said coupling being realized by means of a device that allows the same to become stretched at a predetermined extent, and that comprises the steel spring 6 arranged behind said shoulder 5, said spring working compressively under stress. The last of said energy dissipating members 1 is supported on said shoulder 5 of suitable shape. Each one of said energy dissipating members 1 is provided with an inner guide for the passage of the rope 4. In the case of the first one of said members 1 the guide is oblique in order to allow the rope 4 anchored to the ground to be inserted, whereas in the other members 1 said guide will be horizontal, at a height of about 20 cm. In order to realize a single kind of dissipating member 1 in a way independent of whether said member is to be the leading member or not of the barrier, it can be provided with both a horizontal guide for employing the same as an intermediate or a terminal member, and an oblique guide, in case it is to be employed as the leading member. Reflex reflectors 7 are provided on the energy dissipating members 1. As can be observed in Figure 5, the dissipating members 1 have a cellular structure so that they are elastically deformable in order to be able to absorb the impact energy and to reemploy completely said members after impact. Looking now at the Figures 4a, 4b and 4c, the effects of a front or side impact on a barrier of the structure according to the present invention can be observed. Actually, as a consequence of a front impact (Figure 4b) the maximum kinetic energy dissipation occurs because the particular configuration of said rope 4 allows the direct impact of the first dissipating cylindrical member 1 to occur, which member, translating itself along the rope 4 strikes the successive member 1 and so on, so that the impact energy dissipation occurs at the expense of the deformation energy of the single dissipating members 1, as well as of the change in the momentum occurring in the shifting of the single members 1. In case of a side impact (Figure 4c), the stress of the rope 4 itself that becomes pulled, so compressing the spring 6 against the shoulder 5 adds to the energy dissipating effect caused in this case at a lower degree to the deformation of the single members 1 and to the shifting of such members, said shifting being limited by the stretching possibility allowed by said spring 6 to the rope 4. Finally, the impact dampening by means of the barrier according to the present invention is obtained through: the deformation of the single dissipating member 1 which undergoes directly or indirectly the action of the impact force; the translation and sliding motions along the anchoring rope 4 of the members 1 striken, with the cooperation of a number of said members 1 to the dampening of the impressed kinetic energy; the elastic strength exerted by said predetermined stretch device 6, in case of an oblique impact; the change in the momentum of the single members 1 that overcome the friction force at the contact between a member 1 and the basement (or pavement) 2. Figure 6 shows schematically the application of a barrier according to the present invention near an exit point, but it is evident that such a barrier can be employed in other kinds of applications at places close to openings for traffic divider gates, exit points, roads leading to turnpike gates, and so on. This invention has been disclosed with specific reference to some preferred embodiments of the same, but it is to be understood that modifications and changes can be introduced by those who are skilled in the art without departing from the spirit and scope of the invention as defined in the claims.

Claims: A shock energy dissipating traffic barrier comprising a plurality of aligned dissipating members (1), each one of said members (1) being provided with a transverse guide for the passage of anchoring rope means (4) which are fastened at a point in front of the first of said dissipating members (1) or the leading member of the same, and at a point behind the last one of said dissipating members (1), so that said dissipating members (1) can slide along said rope means (4); said rope means (4) being provided with at least one predetermined-stretch device, characterized in that said members (1) are arranged on the surface of a supporting member (2), in that a bearing member or shoulder member (5) is provided at a point behind the last one of said energy dissipating members (1), said bearing member (5) being rigidly fastened to the supporting member (2) and being so shaped as to couple to the surface of said dissipating member (1), said rope means (4) coming out of said dissipating member (1) being fastened to the bearing member (5), in that said dissipating members (1) have a cellular structure so that they are elastically deformable, and in that said dissipating members (1) are arranged spaced from one another. A shock energy dissipating traffic divider barrier according to claim 1, characterized in that said dissipating members (1) are of cylindrical or elliptical shape. A shock energy dissipating traffic divider barrier according to anyone of the preceding claims, characterized in that each energy dissipating member (1) is about 100 cm high and is of 120 cm diameter. A shock energy dissipating traffic divider barrier according to anyone of the preceding claims, said barrier being characterized in that said dissipating members (1) are made up of rubber or of any other material having a suitable elastic modulus and a suitable deformability. A shock energy dissipating traffic divider barrier according to claim 4, wherein said material has an elastic modulus E equal to 20-80 kg/cm² and a SHORE hardness equal to 20-85 SH/A. A shock energy dissipating traffic divider barrier according to anyone of the preceding claims, wherein 3 or 4 dissipating members (1) are provided. A shock energy dissipating traffic divider barrier according to anyone of the preceding claims, characterized in that it comprises a first dissipating member (1) or leading dissipating member (1) and a terminal or last dissipating member, including a guide for the passage of the anchoring rope means (4), said guide being at a slope, and one or more dissipating members (1) bearing a horizontal guide for the passage of said rope means (4). A shock energy dissipating traffic divider barrier according to anyone of the preceding claims 1-6, characterized in that each one of said dissipating members (1) is provided with a sloping guide and a horizontal guide, said guides being arranged at right angles to one another for the passage of said rope means. A shock energy dissipating traffic divider barrier according to anyone of the preceding claims, wherein said guides for the horizontal passage of said rope means are placed at a level of 20 cm above the ground. A shock energy dissipating traffic divider barrier according to anyone of the preceding claims, wherein said rope means (4) are made up of a steel rope. A shock energy dissipating traffic divider barrier according to anyone of the preceding claims, wherein said predetermined-stretch device of said rope means (4) is arranged on the rope means (4) themselves at the leading position and/or at an intermediate position and/or at a terminal position. A shock energy dissipating traffic divider barrier according to claim 11, wherein said predetermined stretch device is made up of a steel spring that is compressively stressed.

Inventors: STRASSIL CARLO C O C R A CENTR, STRASSIL, CARLO, C/O C.R.A. CENTRO RICERCHE
Applicants: CENTRO RICERCHE APPLICAT, C.R.A. CENTRO RICERCHE APPLICATE S.P.A.
Application year: 1990
Main classification: E01F15
IPC codes: E01F15