SK279987B6 - Metallic safety barrier - Google Patents

Abstract

Metallic safety barrier of the type of EP-A-0428097, which comprises a plurality of modular metallic elements (11) and consists of a frontal absorption panel (12), lengthwise reinforcing elements (13), uprights or stiffening ribs (14) and compartments (25) for the fixture of anchorage bolts (29) to the ground (28), means being included for connecting the modular metallic elements (11) together, the frontal absorption panel (12) extending from an upper front position with an upper portion (35) to a lower intermediate base position, lengthwise reinforcing elements (13) being at least one in number and extending along the length of the frontal absorption panel (12), the uprights or stiffening ribs (14) being equidistant from each other and at least two in number per modular metallic element (11) and having their rear substantially vertical and being sconformed as an "L" and their front portion anchored to the rear of the frontal absorption panel (12) and to the lengthwise reinforcing elements (13 ), the compartments (25) cooperating with a supporting base (19) of the stiffening ribs (14) and with a base segment (26) of the frontal absorption panel (12).

Description

Technical field

The invention relates to metal safety barriers especially suitable for bridges and viaducts, in particular of the type described in EP-A-04228097.

More specifically, the invention relates to crash barriers designed to meet the highest safety standards and having, at the same time, weight characteristics compatible with the conventional type of beam used for road structures, especially for bridges and viaducts.

The crash barrier according to the invention can be used on bridges and viaducts as a central, traffic dividing strip or as a fixed lateral edge, but can also be used in any other solution requiring security means having low weight and high retention capability.

BACKGROUND OF THE INVENTION

The prior art includes several devices intended to improve the safety of driving on modern roads and highways. Among these devices, the so-called protective railings play a very important role.

As is well known, these products have the dual purpose of clearly defining the path for motorists and of preventing the motor vehicle from leaving the road in the event of accidental driver error.

In particular, protective handrails or crash barriers shall enable the following objectives to be attained: large structural strength to maintain and reflect heavy and light motor vehicles; roll-over and high energy absorption capacity, i. flexibility.

In addition, other effects are required, such as functional decoration, for example, permanent green shrubbery, pavement surface drainage and the like.

Good results were obtained by using crash barriers consisting of 7 precast reinforced concrete elements having known profiles and called New Jersey.

These crash barriers, which have been used in several countries for several years now, have a surface inclined at their base and adapted to directly interact with the steering system of motor vehicles heading for collision and thus returning motor vehicles to their own lane as required.

In addition, attempts have been made to avoid the natural stiffness of this type of crash barrier by using a system to anchor the crash barrier type into the ground.

In other words, the crash barriers are provided with their deformation and their residual displacement to allow the deceleration imposed on the motor vehicle to be minimized, thereby achieving acceptable rebound paths and minimal vehicle damage.

The solution described has overcome a large part of the problems on normal road sections, but not on bridges and viaducts.

In fact, the heavy construction of concrete barriers of the New Jersey type is not compatible with loads that would support the normally used load-bearing structures.

Currently, conventional safety barriers made of steel strips are used on bridges and viaducts, which entails well-known limitations, which are even more evident in view of the absolute need to prevent motor vehicles from leaving their lane in these parts of the road.

EP-A-0428097 discloses a safety barrier consisting of modular metallic elements which can be connected to the same elements arranged next to them. This element has side walls for one or more mutually interconnected, joined elements and end walls.

The element is substantially hollow inside and comprises longitudinal reinforcing means and means for attaching adjacent elements together with means for fastening to the ground.

EP-A-0428097, however, describes the formation of a metal crash barrier in which weights and components are required to achieve the desired absorption capacity and structural stability, which impair the weight and stiffness characteristics of the crash barrier and have an adverse effect on both load-bearing structures and driver.

Claims (15)

SUMMARY OF THE INVENTION In order to overcome the shortcomings of the prior art and to achieve further advantages, the present inventors have designed, tested and developed the invention. The invention is described and characterized in the main claim, wherein the dependent claims describe variants of the idea expressed in the main claim. It is an object of the present invention to provide a metal safety barrier which is lighter, but stronger and safer than those described in EP-A-0428097. Another object of the present invention is to provide a fast and secure system for interconnecting adjacent metal elements constituting the barrier. The barrier according to the invention consists of modular metal elements which can be connected to the same adjacent elements to form a safety barrier. Each of these modular elements consists essentially of a frontal metal absorption panel which is longitudinally and transversely reinforced by at least one reinforcing element. The front absorbent panel has a known New Jersey type profile which is formed as an expanding double trapezoid toward its base with a change in inclination in its lower half to enlarge the support base of the modular member and to act in a differentiated manner against the tires of the motor vehicle. The front absorbent panel of the present invention preferably bends rearwardly along a portion of its support base at its lower end. The modular elements are open at the back to make them lighter. The barrier according to the invention weighs about 120 to 140 kg per meter per bar, as opposed to 800 to 1100 kg per meter for normal New Jersey type concrete barriers, and 160 kg per meter for barriers constructed according to EP-A-0428097. The modular crash barrier elements according to the invention comprise at their upper end support means with which at least one suitable longitudinal rod cooperates to provide a further retention effect. This longitudinal retention rod provides additional reinforcement and reinforcement of the safety barrier in the longitudinal and vertical directions and plays a particular role in keeping the motor vehicle on its own lane so as to prevent the motor vehicle from overflowing through the safety barrier. According to another variant, the barrier is provided with two or more longitudinal retention bars. Essentially, in or adjacent to the reference rod support means, the front absorbent panel includes at its top a stiffening support to distribute the load so as to better distribute the pressures transmitted to the retention rod by the absorbent panel at the moment of impact. According to the invention, the points of connection of one retention rod to the other for improving stiffness and reinforcement are preferably offset against the interconnecting ends of adjacent modules forming a safety barrier. The remaining part of the metal structure of the barrier according to the invention has been designed to improve the safety parameters, especially as regards the absorption of kinetic energy, by converting this energy at the moment of impact into a greater deformation of the structure so affected. In addition, this improved design includes improved reinforcing ribs or stiffening posts and new longitudinal reinforcing elements. In addition, the structure is preferably fixed by specific anchor bolts. In this way, the damage caused to persons in the motor vehicle and to the motor vehicle itself is greatly reduced, while at the same time the motor vehicle is reflected off towards the center of its own lane. According to one variant of the solution, the support means with which the retention rod cooperates are located in connection with the reinforcing ribs. In this case, the reinforcing supports that are intended to distribute the load are eliminated. The vehicle according to the invention gives excellent results in terms of maintaining a motor vehicle weighing 30 tonnes and suitable for restraint at a speed of 65 km per hour at an angle of incidence of 30 In the example, the plastic deformation zone is substantially limited to the vicinity of the point of impact of the motor vehicle on the safety barrier. According to another variant, the cover panel may be riveted or otherwise attached to the rear outer face of the front absorbent panels only for aesthetic and not constructional reasons. According to yet another variation, the modules have a metal foot in their lower front part when the safety barrier is attached to a plate arranged at a level above the road bottom. The modular metal elements according to the invention are connected butt together to each other at their ends by means of suitable interconnecting means to form a barrier without any interruption in continuity. According to another variant, the connecting means comprises a horizontal plate attached to the upper end of the front absorbent panels and fixedly attached e.g. screws and nuts to the two modules to be joined. According to a further variant, the means which connect the modular metal elements consist of a double hinge, the meshes of which are fixedly attached to the end reinforcing posts. The interface plate with customized interface eyes cooperates with these eyes. Installation and subsequent interconnection of adjacent modular metal elements provided in accordance with this variant are accomplished by placing an interconnecting plate between two adjacent modular metal elements with meshes on the same axis as the meshes of the two adjacent modular metal elements, interposing two pins cooperating from above. with matching meshes. According to a further variant, the double hinge preferably extends partially along the top of the modular metal elements. The modular metal members of the invention may also include specific hooks for attachment to pre-existing modules of another type of metal. Each modular metal element comprises a ground anchoring means. These anchoring means are preferably of the resilient type and spring-loaded to provide the desired resilient resistance to the pressures due to the impact of the motor vehicle. The means for anchoring the modular metal members to the ground consist of a set of anchor bolts which cooperate with respective beds machine-made at the bottom of the modular metal members and which are anchored in the pavement slab. These beds cooperate directly with structural elements providing vertical reinforcement and consisting of reinforcing ribs or posts. According to one variant, where the bridges are made of steel, the anchoring means consist of anchor bolts cooperating with tubes or strips attached to the inside of the metal structure of which the bridge consists. The stiffening ribs, which are at least two for each modular metal element, are rigidly connected to the inner surface of the front absorbent panel to form a single body. The longitudinally reinforcing element, which is suitably shaped, such as the letter V, with its wide sides anchored firmly in the rear wall of the front absorbent panel, is substantially as long as the modular metal element and is positioned at a height ranging from 0.3 to 0, 6, preferably 0.45 of the height of the front absorbent panel of the metal barrier according to the invention. According to a further variant, the longitudinal reinforcing element consists of an inner element curved in a V-shape or preferably of a dovetail-shaped element formed in the front absorbent panel. In this case, the barrier may be provided with vertical connecting bridges separated from one another by the horizontal flanges of the inner pleats. According to another variant, the two or more longitudinal reinforcing members cooperate with the front absorbent panel. Where there are two elongated elements, the upper one is mounted at an elevated height between 0.3 and 0.6, preferably 0.45, of the height of the front absorbent panel, while the lower one cooperates, preferably through one of its sides with the apex of the front inclination absorption panel. The reinforcing ribs have an L-shaped cross-section, the long side of which has a variable length to accommodate the front absorbent panel. More specifically, the long side of the L-shape is raised downwardly so that its free end is attached to the rear face of the front absorbent panel to which it is rigidly connected. The rear vertically located short sides of the ribs are facing away from the side from which the vehicles come. In the long side of the stiffening ribs, substantially V-shaped grooves are arranged in a number corresponding to the number of longitudinal stiffening elements. These grooves allow the longitudinal stiffening elements to pass and be positioned against the rear surface of the front absorbent panel. The stiffening ribs are bent at their lower end to form a support base that cooperates endwise with the lower edge of the front absorbent panel, which is preferably curved. Overview of the figures in the drawing The accompanying drawings, which are to be understood as non-limiting examples, illustrate some preferred embodiments of the invention. Fig. 1 is a front axonometric view of a metal safety barrier structure according to the invention; FIG. 2 is a rear view of a metal barrier according to the invention, FIG. 3 is a longitudinal section of the metal barrier along line D-D of FIG. 4 together with an enlarged detail of the type of connection between adjacent elements; FIG. 4 is a cross-sectional view of the metal barrier along line A-A in FIG. 2, FIG. 5 is a cross-sectional view of a variant of the metal barrier of FIG. 4, FIG. 6 is a cross-sectional view of the type of anchoring of the metal barrier of FIG. 4 to the ground, FIG. 7 is an enlarged cross-sectional view of the reinforcing rib taken along the line B-B in FIG. 2, FIG. 8 shows a vertical longitudinal section through the reinforcing rib along line C-C of FIG. 7, FIG. Figures 9 to 13 show sections of some exemplary embodiments of metal crash barriers according to the invention; Fig. 14 is a rear view of another exemplary embodiment of a metal barrier according to the invention; Fig. 15 is a rear view of a metal barrier according to the invention showing a different type of connection of different elements; 16 is a horizontal cross-section of the metal barrier of FIG. 15 taken along line E-E; and FIG. 17 and 18 are cross-sections of two types of anchoring of a metal barrier according to the invention to a metal structure. Fig. 1 shows a safety barrier 10 consisting of an array of modular metal elements 11 disposed adjacent to each other and connected together. The modular metal elements 11 include means for attaching them to the ground 28. The frontal adaptation of the modular metal elements 11 is similar to that of the New Jersey type and contains good tested advantageous properties of this type. The modular metal member 11 comprises a shaped front absorbent panel 12 having a crest 32 at its lower part, coinciding with a tilt change of the front absorbent panel 12. In the examples of FIG. 2, 4, 5 and 8, the front absorbent panel 12 comprises two reinforcing elements 13 arranged longitudinally along its rear surface, having substantially the same length as the modular metal element 11. The first lower reinforcement element 13a is fixed with one side just below the apex 32 of the front absorbent panel 12, while the second higher longitudinal reinforcement element 13b is located at an elevation of between 0.3 and 0.6, preferably 0.45, of the height of the front absorbent panel. panel 12 of the metal barrier 10 according to the invention. According to the variant of FIG. 9, 10, 11, 12 and 13, the front absorbent panel 12 comprises only one reinforcing element 13b that is disposed along the rear wall of the panel 12 and has substantially the same length as the modular metal element 11. According to a further variant, the reinforcing element 13b is obtained by bending the front absorbent panel into the dovetail shape, see FIG. 11th Further, the front absorbent panel 12 comprises a set of substantially vertical stiffening ribs 14 that are at least two on each modular metal member 11a are equally spaced and attached to the front absorbent panel 12 and the stiffening members 13. In the example of FIG. 2 shows a metal crash barrier 10 having each module metal element 11 provided with six reinforcing ribs 14. The ribs 14 have an L-shaped cross-section along a horizontal plane, see FIG. 7. The long side 14a of this L has a variable length that is adapted to the profile of the front absorbent panel 12 to which the ribs 14 are rigidly attached. The substantially V-shaped grooves 33 are also machined in the long wall 14a of the stiffening ribs 14 and have a shape and a position coordinated with the longitudinal stiffening elements 13a and 13b. Where there is only a reinforcing element 13b, e.g. Fig. 10, 11, 12, 13, the stiffening ribs 14 are provided with only one groove 33, the shape and position of which are coordinated with the longitudinal stiffening element 13b. The stiffening ribs 14 are bent at their lower part to form a support base 19 that end-cooperates both with the front absorbent panel 12, which is folded backward to form the base 26, and with the ground 28. The beams 15 that extend above the front absorbent panel 12 also cooperate with the upper portion 35 of the panels 12 and with the vertical reinforcing ribs 14. With these beams 15, there is a retention rod 16 which extends along the entire length of the safety barrier 10. The beams 15 are bent forward such that the retention bar 16 protruded in front of the nearly vertical top surface of the front absorbent panel 12. In the beams 15, the front absorbent panel 12 is provided with a reinforcing and pressure-distributing V-shaped support 17 at its upper part to receive and distribute the pressures exerted by the retention rod 16 on the front absorbent panel 12 at the moment of impact of the motor vehicle. According to one variant, see FIG. 14, the beams 15 adjoin the vertical reinforcing ribs 14, and in this case the reinforcing and pressure-distributing supports 17 are omitted. According to another variant, see FIG. 14, the beams 15 are connected to at least the end stiffening ribs 14 and also act as fastening means 20. The retention bars 16 are preferably interconnected by interconnecting sleeves 18 in which the ends of adjacent retention bars 16 are fastened. According to one variant, see FIG. 13, the front absorbent panel 12 has a reduced height ranging from 0.5 to 0.8 of its normal height, and is provided with at least two retention bars 16. The stiffening ribs 14, located at the end of the modular metal element 11, comprise mutually adapted interconnecting means 20 to form an interconnection of two adjacent metal elements 11. These interconnected coupling means 20 in the examples of FIG. 2 and 3 consist of a hinge comprising a set of meshes 21 arranged on the stiffening ribs 14 and a connecting plate 20 which also includes on each of its sides a set of meshes 23 in coordinated positions. The interconnection of two adjacent modules of metal elements 11 is achieved by the fact that each of the two pins 24 cooperates with the eyes 21 of the respective reinforcing rib 14 and with the corresponding eyes 23 of the connecting plate 22, which are suitably centered with the eyes 21 of the rib 14. For clarity, the pins 24 are shown only partially inserted into the respective eyes 21 to 23. In the case of road twists or other types of deviation, it is sufficient to suitably change the dimensions and / or shape of the connecting plate 22 so that adjacent modular metal elements 11 can be interconnected. According to one variant, see FIG. 14, the hinge is arranged only partially along the reinforcing ribs 14 of the metal barrier 10 according to the invention. According to another variant, see FIG. 15 and 16, the interconnecting means 20 formed from the horizontal plate 36, disposed on the upper side 35 of the front absorbent panel 12, two adjacent modular metal elements 11a are connected to the elements 11 by suitable screws and nuts 37. By joining and fastening the opposing rear surfaces of the two module metal elements 11, it is possible to form a central protective strip. It is only for aesthetic reasons that it is possible to attach a panel to the rear of the modular metal element 11 which covers the longitudinal reinforcing elements 13 and the reinforcing ribs 14. The surface of this panel can be used e.g. for sticking advertising posters. Fig. 6 illustrates an exemplary embodiment of means 30 for resiliently anchoring the modular metal element 11 to the ground 28. Each modular metal element 11 comprises at its lower portion an array of chambers 25 formed on the base 26. Each chamber 25 comprises a reinforcing plate 34. The openings 27 are machine-formed in the base 26 and adjoin the chambers 25 and the anchor bolts 29 are inserted through the openings 27. These anchor bolts 29 are retracted preferably by a dynamometric wrench or screwdrivers calibrated to achieve the desired bias value. The reinforcement plate 34 rests on the support base 19 and is supported on the base 26. This has the effect that the resilient attachment of the anchor bolts 29 cooperates with the safety barrier 10 without creating localized points at which impact energy would be consumed. Where the safety barrier 10 is attached to the plate raised above the road bed 28, the modular metal element 11 comprises at its lower end a connecting foot 31, see figures 5, 10 and 18. According to a variant where the bridge is made entirely of steel, the anchoring means 30 consist of anchor bolts 29 which cooperate with pipes or strips 38 fixed inside between the upper plate 40a and the lower plate 40b of the metal structure forming the base 39 of the steel bridge. In the examples of FIG. 17, 18, the stiffening ribs 42 are secured below the top plate 40a. The tube 38, which is substantially coaxial to the anchor bolt 29, is rigidly attached to the top plate 40a forming the base 39 of the steel bridge and includes in its lower part 44 an opening 41 with which the anchor bolt 29 cooperates. In the example of FIG. 18, the metal bridge comprises a plate 43 that is raised above the road bed 28 and with which a connecting foot 31 formed at the lower end of the modular metal member 11 cooperates. In this example, the tube 38 is rigidly attached to the plate 43 and the upper plate 40a through 38 passes. PATENT CLAIMS A metal safety barrier of the type EP-A-0428097, comprising an array of modular metallic elements and consisting of a front absorbent panel, longitudinal reinforcing elements, columns or reinforcing ribs and chambers for fastening the anchor bolts to the ground and comprising means for interconnecting the modular elements metal elements, characterized in that the front absorbent panel (12) is arranged between the upper front position with the upper portion (35) and the lower middle base position, wherein at least one longitudinal reinforcing element (13) is disposed along the length of the front absorbent panel (12). ) and at least equally spaced apart, at least two columns or stiffening ribs (14) are provided in each modular metal element (11), the rear part of which is substantially vertical and which are L-shaped and have their front part anchored to the rear part of the front part of the absorbent panel (12) and the like an elongate stiffening element (13), the stiffening ribs being rigidly connected to the support base (19) on which the chambers (25) are formed and to the base segment (26) of the front absorbent panel (12). A barrier according to claim 1, characterized in that the longitudinal reinforcing element (13) is V-shaped with its sides opening towards the front absorbent panel (12). A barrier according to claim 1 or 2, characterized in that the longitudinal reinforcement element (13) is arranged along the rear of the front absorbent panel (12) and is continuously in contact with the front absorbent panel (12). A barrier according to any one of the preceding claims, characterized in that at the top (35) of the front absorbent panel (12) there are beams (15) carrying at least one retention rod (16) disposed along and above the modular metal elements (11). A barrier according to any one of the preceding claims, characterized in that the retention rod (16) is advanced and cooperates with a projection of the upper, almost vertical surface of the front absorbent panel (12). A barrier according to any one of the preceding claims, characterized in that it comprises a pressure-distributing support (17) cooperating with each beam (15) and supported on the inner upper part of the front absorbent panel (12). A barrier according to any one of the preceding claims, characterized in that each beam (15) is positioned in relation to the reinforcing rib (14). A barrier according to any one of the preceding claims, characterized in that it comprises a beam (15) arranged as a connection to the lifting means (20) adjoining the end of the reinforcing rib (14). A barrier according to any one of the preceding claims, characterized in that the first lower longitudinal reinforcing element (13a) has one of its longitudinal edges at the peak (32) of the inclination of the front absorbent panel (12) and is attached to the lower, almost vertical surface. of this panel (12). A barrier according to any one of the preceding claims, characterized in that the second reinforcement element (13b) arranged above is located at an elevation between 0.3 and 0.6 of the height of the front absorbent panel (12). A barrier according to any one of the preceding claims, characterized in that the L-shaped rear portion of the reinforcing ribs (14) formed on the side opposite the direction of travel of the motor vehicle comprises a reinforcing extension. A barrier according to any one of the preceding claims, characterized in that the chamber (25) comprises a reinforcing plate (34) and side walls providing reinforcement and interconnection. A barrier according to any one of the preceding claims, characterized in that the connecting means (20) are designed as a vertical connecting plate (22) cooperating with the connecting pins (24), the vertical connecting plate (22) being arranged vertically along at least part of the height the end of the apt rib (14). A barrier according to any one of claims 1 to 12, characterized in that the connecting means (20) are designed as a horizontal plate (36) cooperating by means of screws and nuts (37) with the upper ends of the modular metal elements (11) located next to themselves. A barrier according to any one of the preceding claims, characterized in that the height of the front absorbent panel (12) is reduced by 0.5 to 0.8 times its normal height.