"Steel traffic divider road safety barrier"

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The present invention relates to a steel traffic divider road safety barrier.

In particular, the present invention relates to a steel traffic divider road safety barrier, of the type made of a continuous three-wave steel and comprising an MPS (Motorcyclist Protection System), used for the safety of roadways .

As it is known, increasing road infrastructure safety can be achieved by simultaneously operating on factors that affect both active road safety and passive road safety. Active road safety is influenced by all those measures that aim to increase the likelihood that road accidents will not occur (consistent and clearly readable roadways, adequate free views for stopping, efficacy of road signs, good grip provided by the roadway, night lighting, etc.)

The aids used to ensure adequate levels of passive safety of the roadway, usually, are installed with the aim of reducing the damages, both to people and to things, deriving from the occurrence of an accident. Among the passive safety devices, a primary role is played by the restraint systems which, as regulated by the Italian laws, are installed essentially in order to achieve acceptable safety conditions, both for road users and for any third parties eventually present, in relation to the configuration of the road, ensuring, within certain limits, the containment of vehicles that may tend to come out from the roadway. These functional features presuppose that the restraint systems must be suitable for absorbing part of the energy of the impact and, at the same time, reducing the damages to the occupants of the vehicles following an impact. Furthermore, as a result of the impact, the vehicle has not to cross the road barrier, in order to preserve what is beyond the containment structure, and must gradually re-enter the road and not interfere, as much as possible, with vehicles in transit and with other traffic parts allowed to transit over the roadway.

The design, the approval and the installation of the road restraint systems, in Italy, have to comply with the European Regulation UNI EN 1317, parts 1-4, and with the Laws n°223, dated March 16, 1992, and n°2367, dated June 21, 2004, and with the Ministerial Directive dated August 25, 2004. It is usual, also with reference to what is prescribed by the Italian laws (ref. art. 1, law dated 21 June, 2004), to classify the road safety barriers in relation to their destination and positioning. Considering the different areas that may need specific protection, the barriers are divided into: traffic divider barriers, positioned along the center lines that separate the roadways, or as restraint systems placed at the edges of the roadway, at the edges of bridges or at the edges of tunnels, with the aim to restrain and redirect vehicles according to optimized trajectories following an impact. In addition, these road safety barriers have the function of absorbing part of the kinetic energy possessed by the vehicle in the impact against the barrier. Depending on the material making up the barrier, it is possible to consider steel barriers, concrete barriers, wood barriers having a steel core, where environmental needs require this latter type. Furthermore, the materials with which the road safety barriers are built must comply with essential requirements concerning mechanical strength and durability, in addition to features related to environmental compatibility and aesthetic qualities, when required.

According to their more conventional configuration, the steel barriers consist of the following structural elements: uprights, frames on the ground or fastened with bolts to a support; one or more steel strips, generally consisting of one or more two-wave or three-wave shaped sheets; longitudinal handrails, i.e. elements arranged parallel to the strip, at the bottom (wheel guard) or at the top of the barrier; spacers, which, if present, are placed between the strips and the uprights, having the function of dissipating the energy of light impacts ensuring the effect of the rising of the steel strip during the impact, in order to prevent a vehicle from climbing over the barrier; bracing diagonals, if present; connecting and anchoring bolts; supports for anchoring or for fixing the uprights.

In addition, the safety barriers are divided into energy resistance classes that vary in their upper range, starting from a minimum (HI level) up to a maximum (H4 or H4b level) according to the classification of the European Regulation EN 1317, which allows the shock absorption followed by a displacement contained within a predefined space and with a certain homogeneity of behavior, in addition to the control of decelerations without damages to the occupants of vehicles, in the event of a collision of light vehicles, and to free falling motorcyclists. Two of the parameters that characterize the dynamic performance of the road safety barriers are the working width Wm, defined as the distance between the side facing a roadway before the impact and the maximum lateral dynamic position of the barrier itself, and the dynamic deflection Dm, defined as the maximum lateral displacement of the side of the barrier facing the roadway. Two other performance parameters of road safety barriers, which specify their behavior following an impact, are the aforementioned ASI

(Acceleration Severity Index) and the THIV (Theoretical Head Impact Velocity), whose combination allows to express the severity level of the impact, within a range expressed by the three classes 'A', 'B' and 'C .

Furthermore, additional parameters concerning road safety barriers define the containment level of said barriers following the impact with a heavy vehicle and the severity of the impact with a light vehicle, according to a reference scale indicated with the abbreviations 'T', 'N',

’L’ or Ή '.

Several traffic divider road safety barriers, characterized by different geometry, performances and features, are currently known.

A first known solution is disclosed in the Italian patent ITMI20110674A1, which describes a road safety barrier, used as a side barrier or as a traffic divider, made of concrete or three-wave steel with spacers and uprights. The purpose of the invention is to produce the barrier with containment levels up to H4, able to make the response to the impact homogeneous, regardless of the characteristics of the terrain and the roadway, and to reduce the damages to motorcyclists after an impact. A second known solution is described by the European patent EP2108741A2, whose subject is a road safety barrier designed to limit the damages in the event of motorcycle accidents, comprising a plurality of upright stakes which support the barrier arranged at a predetermined height from the roadway, deformable spacers made of shaped steel sheet mounted on the stakes and a set of corrugated strip steel segments, fixed to the spacers so as to be placed between the roadway and the safety barrier at a fixed distance from the stakes.

A third known solution is disclosed in the European patent EP2088247A2, which describes a safety device for motorcyclists, especially designed to be used in safety barriers located along the edges of roads or along the motorway center lines, characterized in comprising an W- shaped element directly anchored to the stakes supporting the barrier by means of strip elements made of stainless steel.

Finally, the Italian patent application BN2010A000004 describes a H4b two-wire three-wave steel traffic divider barrier, to be used in a single row also along the edges of the roadways. The protection uses riser spacers, it is suitably reinforced with diagonal tubes and with an upper longitudinal handrail, and with a steel bar locked with clamps to each upright stake. A further protecting element, particularly useful for cars, consists of a second lower spacer characterized by a progressive failure connected to the stake and supporting a longitudinal C-shaped wheel guard. However, the traffic divider technical solutions currently known have performances, in terms of acceleration to which the occupants of a vehicle are subjected in the event of an impact, and of working width W _m of the impacted barrier, not optimized. These parameters are particularly relevant in case of installation in limited areas, such as not to allow the installation of a safety barrier wide enough.

The purpose of the present invention is to provide a steel traffic divider road safety barrier able to allow the installation of restraint systems in limited spaces ensuring an adequate restraining and redirecting action on impacting vehicles and reduced values of parameters such as, specifically, the working width W _m , the dynamic deflection D _m and the ASI index so as to allow the installation and the right functioning on roadways characterized by limited spaces having, therefore, characteristics such as to overcome the limits that still affect the current road safety barriers with reference to the known technique. According to the present invention a steel traffic divider road safety barrier is provided, as defined in claim 1.

For a better understanding of the present invention a preferred embodiment is now described, purely by way of a non-limiting example, with reference to the attached drawings, in which:

- figure 1 shows a cross sectional view of a steel traffic divider road safety barrier, according to the invention;

- figure 2 shows a detailed cross-sectional view of the steel traffic divider road safety barrier, according to the invention; figure 3 shows a detailed schematic view of a portion of the barrier shown in figure 2, according to the invention; figures 4a, 4b and 4c show schematic views of portions of the barrier of figure 2, in particular, respectively of a three-wave strip, of a motorcyclist protection system and of an assembly of these elements, according to the invention.

With reference to these figures and, in particular, to figure 1 and figure 2, a steel traffic divider road safety barrier is shown, according to the invention. In particular, the traffic divider road safety barrier is made of steel, and comprises:

- - an upper safety bar 100a and a lower safety bar 100b, said lower safety bar 100b placed at a predetermined height from the roadway;

- a plurality of vertical uprights 101 configured to support the upper safety bar 100a and the lower safety bar 100b; and

- at least a strip 103, preferably a three-wave strip; a plurality of spacers 102 fixed to the corresponding vertical uprights 101 and placed between the vertical uprights 101 and the at least a strip 103.

The traffic divider road safety barrier 1, comprises also at least a motorcyclist protection system 104 placed below the at least a strip 103 and fixed to a lower portion of each vertical upright 101 comprised in the plurality of vertical uprights 101.

As shown in figure 1, according to an aspect of the invention the traffic divider road safety barrier 1 comprises at an upper portion at least a handrail 105, fixed to the plurality of vertical uprights 101 at a height corresponding to the height of the upper safety bar 100a from the roadway.

According to an aspect of the invention, each vertical upright 101 comprises a first sleeve 100a' for blocking the upper safety bar 100a, and a second sleeve 100b' for blocking the lower safety bar 100b to said vertical upright 101.

In particular, each vertical upright 101 comprised in the plurality of vertical uprights 101 placed in series along the roadway, has a second sleeve 100b' for fixing the lower safety bar 100b. Subsequent vertical uprights 101 have second sleeves 100b' mutually staggered, i.e. alternatively placed at an inner and at an outer side of the vertical upright 101 to which they are fixed.

According to an aspect of the invention, the lower safety bar 100b is placed at a height of less than 100 cm from the roadway and, preferably, equal to 84 cm from the roadway. Advantageously according to the invention, the lower safety bar 100b allows to double the kinematic operating mechanism necessary for the correct functioning of the barrier 1. In fact, unlike the existing barriers which have only one steel bar positioned at about 140/150 cm from the roadway and having a restraining and redirecting function of the vehicles after an impact with a redirecting angle similar to the impact angle, in the present invention, the vehicle containment and re-addressing mechanism following the impact with a return angle similar to the impact angle, has been doubled thanks to the insertion of the additional lower safety bar 100b.

According to an aspect of the invention, the three- wave strip 103 has two concave portions and three convex protrusions forming an angle of 8° with the vertical when, in use, the three-wave strip 103 is fixed to the spacer 102 at the two portions concave. Preferably, the three-wave strip 103 has a thickness of 3 mm.

According to another aspect of the invention, the spacer 102 is placed between the vertical uprights 101 and the strip 103, allowing a controlled deformation in the event of an impact.

As shown in Figure 3, the spacer 102 comprises a first shaped element 102a having a substantially semi-circular section, shaped so as to have three concave sides, and a flat element 102b, preferably welded between the ends of the first element 102a, and able to be fixed to a vertical upright 101.

According to an aspect of the invention, the spacer 102 further comprises a L-shaped second element 102c fixed to an upper portion of the first element 102a and to the vertical upright 101. The second L-shaped element 102c forms an angle preferably equal to 82° between the point of fixing to the vertical upright 101 and the fixing point to the upper portion of the first shaped element 102a of the spacer 102.

The first shaped element 102a has the function of deforming in the event of an impact, while the L-shaped second element 102c has the function of calibrating the deformation with respect to the rigidity of the vertical upright 101.

In addition to the thickness of the sheet through which the spacer 102 is made, the calibration of the deformation is due to the particular shape of the first shaped element 102a. In particular, the first shaped element 102a of the spacer 102 has a section having an upper curvilinear portion and a lower curvilinear portion mutually opposite, the upper curvilinear portion having a length greater than the length of the lower portion and being fixed by fixing means, preferably bolts, to the L- shaped second element 102c. The first element 102a also has the plane element 102b fixed to the vertical upright 101 and a curvilinear portion, opposite to the flat element 102b, having two fixing points to the three-wave belt 103, and a central portion protruding, with respect to the two fixing points.

Advantageously according to the invention, the spacer 102, and in particular the first shaped element 102a, is able to be made as a single piece, with no needs of welding.

According to an aspect of the invention, the upper safety bar 100a is a steel bar with a diameter of 24 mm, placed into the first locking sleeve 100a', for fixing the bar to each vertical upright 101. The upper safety bar 100a and the first locking sleeve 100a' are placed inside an upper reinforcement element fixed by bolts to the handrail 105, on both of its sides, so as to achieve the connection between the vertical upright 101 and the handrail 105.

According to one aspect of the invention, the upper safety bar 100a is placed at a height comprised between 130 cm and 160 cm from the roadway, preferably at a height of 144 cm.

According to an aspect of the invention, the lower safety bar 100b is placed at a height from the roadway less than or equal to the height from the roadway of the fixing point of the second element 102c of the spacer 102 to the vertical upright 101, as shown in figure 2.

According to an aspect of the invention, the barrier 1 is made in its parts of steels having different mechanical characteristics, and in particular: the spacer 102 and the motorcyclist protection system 104 are made of Fe360B steel, the handrail 105 for covering the bars is made of Fe510B steel, the strip 103 is made of Fe430B steel. According to one aspect of the invention, the lower safety bar 100b is made of B450C steel and has a diameter preferably of 24 mm.

According to one aspect of the invention, the upper safety bar 100a is made of B450C steel and has a diameter preferably of 24 mm.

Advantageously, the geometrical and mechanical features and the choice of materials according to the present invention ensure an optimal response of the barrier in case of impact.

According to one aspect of the invention, each vertical upright 101 has a C-shaped profile.

Following the Italian Law dated April 1, 2019, also in Italy it became necessary to evaluate, under certain conditions, the effects of an impact of a motorcyclist with the safety barrier, in accordance with the UNI CEN/TS 1317- 8 regulation.

Advantageously, the traffic divider barrier according to the invention does not need to be validated since it has a continuous profile along the roadway, that is, the strip 103 and the motorcyclist protection system 104 are installed without interruption between them.

According to an aspect of the invention and as shown in figure 4c, the motorcyclist protection system 104 is fixed to each vertical upright 101 by means of a U-shaped element 106, provided with a pair of slots for fixing by bolts, and a steel bar 107, parallel to the strip 103 and placed between each U-shaped element 106 and the respective vertical upright 101. Preferably, the U-shaped element 106 has dimensions equal to: height 90 mm, width 50 mm, depth 45 mm.

According to an aspect of the invention, as also shown in figure 1, the steel traffic divider road safety barrier 1 has a symmetrical structure with respect to a line of vertical symmetry passing through the center of the vertical upright 101, thus comprising for each vertical upright 101 two three-wave strips 103, two motorcyclist protection systems 104, two spacers 102, two handrails 105, placed symmetrically on opposite sides of the plurality of vertical uprights 101.

The Applicant has carried out crash tests on the traffic barrier according to the invention, aimed at evaluating its performances. As required by the UNI EN 317 regulation, two different tests were carried out: a first test using a light vehicle (TB 11), the other using a heavy vehicle (TB 81) launching a 38-tons truck at a speed of 65 km/h with an impact angle of 20°. Both tests gave positive results: the TB 11 test, using a light vehicle, has advantageously shown that the accelerations to which the vehicle occupants are subjected, i.e. anthropomorphic dummies, are comprised within the limits fixed by the regulation; the TB 81 test, carried out using a heavy vehicle, provided an extremely important index concerning the working width "W" of the impacted barrier whose achieved value is unique within the limits of same containment class. Advantageously, in fact, the tests have shown that a traffic divider according to the present invention and having a width of only 76 cm allows to have a value of W4 equal to 1,28 m, such as to allow to solve problems related to limited plant conditions, for example the installation of restraint systems on existing roads characterized by limited space.

Moreover, the Applicant carried out experimental tests using an anthropomorphic instrumented dummy, in order to evaluate the potential damages suffered by a motorcyclist following an impact with the lower part of the traffic divider, according to the European technical specification UNI CEN/TS 1317-8. Advantageously, the continuous motorcyclist protection system 104 allows to prevent the end parts of the body of a motorcyclist from coming into contact with sharp portions of the barrier, particularly with the vertical uprights 101.

Advantageously according to the invention, the steel traffic divider road safety barrier 1 has a containment level H4b. Advantageously according to the invention, the steel traffic divider road safety barrier has a minimum deformation, in terms of working width (W), i.e. the maximum side distance between the side of the barrier oriented towards the road traffic before the impact and the maximum dynamic side position of any portion of the barrier following the impact, particularly useful for the use of the barrier itself in limited spaces.

Therefore, the steel traffic divider road safety barrier according to the invention ensures an optimized response to the impacts characterized by limited maximum deformations, even in installation conditions with reduced spaces.

Another advantage of the steel traffic divider road safety barrier according to the invention is that it is of easy production.

Another advantage of the steel traffic divider road safety barrier according to the invention is that it is inexpensive . It is finally clear that the steel traffic divider road safety barrier described and illustrated herein can be subject to modifications and variations without departing from the protective scope of the present invention, as defined in the appended claims.