ROAD EQUIPPED WITH ROAD SAFETY BARRIERS FIXED TO THE GROUND AND INSTALLATION METHOD THEREOF

Abstract

The present invention relates to the installation of road safety barriers also known as guardrails; and indicates a real road system, including special safety barriers, in which each trait of the safety barrier can be installed with the reasonable certainty of compliance with the required safety requirements, and these requirements can be defined differently depending on the trait.

Furthermore, this road system, including special safety barriers, is associated with an innovative installation and maintenance method, which is not significantly more expensive than the methods currently practiced for the installation and maintenance of simple road barriers, in which the fixing of the uprights to the ground is done by simple infixion into the ground using a pile-driving machine.

The invention is characterized by an appropriate ground fixing system, which is integrated in said guardrail.

Claims

1. A road with a stabilized road substrate (201) consisting of a ground with known compactness characteristics on which a road surface (210) is spread, and equipped with a safety road barrier comprising a plurality of uprights (110), fixed in the edge of the road as in the known art, and wherein said safety barrier comprises at least the elements: a. a system of vertical plates (153), with a thin section, infixed on said road substrate (201) below said road surface (210); b. a junction element (151) arranged to be coupled to an upright (110) of a road safety barrier by wrapping them around its base; c. a connecting tie rod (152) lying, or slightly buried, on the road substrate (201), which is: i. coupled to said system of vertical plates (153) at one of its ends, and ii. releasably coupled to said junction element (151) at its other end; and said junction element (151) comprises parts with programmed breakage; and said programmed breakage is designed to happen when the following conditions occur: said connecting tie rod (152) exerts a traction force on said junction element (151) higher than a predetermined threshold, and said connecting tie rod (152) exerts a traction force on said junction element (151) lower than the force that would damage said connecting tie rod (152) or to the force that would cause a displacement of said system of vertical plates (153) with respect to the road substrate in which it is infixed.

2. The road according to claim 1 wherein said system of vertical plates (153) has a cross-shaped section.

3. The road according to claim 1 wherein said junction element (151) comprises: c. a U-shaped element (151.1), the size of which is suitable for wrapping said uprights (110) of a road safety barrier; d. a closing bar (151.3), arranged to close said U-shaped element (151.1), hooking at its two ends, so as to completely envelop an upright (110) of a road safety barrier; and said closing bar (151.3) has at least one hole (151.4), being the width of said hole (151.4) adjustable and correlated, by means of a known function, to the traction force that must be exerted on said connecting tie rod (152) so that said closing bar (151.3) breaks.

4. The road according to claim 1 wherein each upright (110) of a sequence of consecutive uprights (110), infixed in the roadside, is connected to at least two of said systems of vertical plates 153, and each of said systems of vertical plates 153 is connected to at least two uprights (110).

5. The method of installing a safety road barrier for making a road according to claim 1 starting from a pre-existing road in which the roadway comprises a road substrate (201) and a road surface (210) made with an asphalt layer; and this installation method includes at least the steps listed below: a. cutting of the asphalt with which said road surface (210) is made i. according to the shape of the section of said system of vertical plates (153), and ii. according to a line that connects the previous cut and the position where the installation of a guardrail upright is planned; b. hooking said connecting tie rod (152) to said system of vertical plates (153) and laying it inside the cut referred to in point ii. above, so that after installation, said tie rod is laid on the road substrate (or slightly buried) below the level of the road surface; c. driving the system of vertical plates (153) by means of a pile-driving machine, so that it is substantially buried entirely in the road substrate (201) or protrudes from it for a very small part in comparison with the thickness of the road surface (210) above; d. coupling said junction element (151) to the end of the connecting tie rod (152) which is located near the point where the upright (110) of a road safety barrier must be fixed; e. driving said upright (110) of a safety road barrier, by means of a pile-driving machine so that said upright (110) slips into said junction element (151) remaining hooked to it; f. tensioning said connecting tie rod (152) by means of a suitable maneuver performed on said joining element (151); g. sealing of the cuts made on the asphalt paving.

6. The method for creating a road according to claim 1 starting from a road in which the roadway, composed of said road substrate (201) and said road surface (210), is pre-existing and said road is already equipped with a safety road barrier, installed by simple infixion of the uprights (110) into the ground at the edge of the road; and this manufacturing method includes at least the steps listed below: a. cutting of the asphalt with which said road surface is made (210) i. according to the shape of the section of said system of vertical plates (153), and ii. according to a line that connects the previous cut and the position where the upright of a guardrail is planted; b. hooking said connecting tie rod (152) to said system of vertical plates (153) and laying it inside the cut referred to in point ii. above, so that after installation, said tie rod is laid on the road substrate (or slightly buried) below the level of the road surface; c. driving the system of vertical plates (153) by means of a pile-driving machine, so that it is substantially buried entirely in the road substrate (201) or protrudes from it for a very small part in comparison with the thickness of the road surface (210) above; h. coupling said junction element (151) to an upright (110) of the road safety barrier with which said road is equipped; i. coupling said junction element (151) to the end of the connecting tie rod (152) which is located near the point where it is infixed the upright (110) of the safety road barrier, that is the same upright to which said junction element (151) had previously been coupled; j. tensioning said connecting tie rod (152) by means of a suitable maneuver performed on said joining element (151); k. sealing of the cuts made on the asphalt paving.

7. The method according to claim 5 in which the asphalt cutting phase, indicated in both claims at point a., is completed with an asphalt core drilling operation aimed at removing small parts of the road surface (210) so as to be able to drive into the underlying road substrate (201) also systems of vertical plates (153) which have enlargements in their section.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0063] The main advantage of the present invention consists in the fact that any upright for guardrail installed according to the teachings of the present invention satisfies all the main requirements for which it was conceived, designed and certified.

[0064] Moreover, this invention also has further advantages, which will become more evident from the following description, from some examples of practical embodiments which illustrate further details, from the attached claims which form an integral part of the present description, and from the attached figures in which:

[0065] FIGS. 1a and 1b show the main elements of a safety road barrier (guardrail);

[0066] FIG. 2 shows a guardrail according to the known art, fixed to the base by driving the uprights into the ground;

[0067] FIG. 3 shows, in a simplified way, a perspective view of some details of an installation of an upright for guardrail according to the invention;

[0068] FIGS. 4a and 4b show two examples of implementation of a junction element in a guardrail system according to the invention;

[0069] FIG. 5 shows, in a simplified way, a plan view of an installation of some uprights for guardrails according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0070] FIG. 1a shows a section of a typical road safety barrier (also called a guardrail). This barrier is seen from inside the road and, in general, it is composed of the elements listed below: [0071] substantially vertical elements, normally called uprights, which support the barrier itself, and indicated with the number 110 (also in the following figures); [0072] a horizontal containment metal strip, indicated with the number 130 also called horizontal blockout bar; [0073] an eventual upper beam, indicated with the number 140.

[0074] The uprights 110, in a typical and widespread installation method, are fixed to the base by driving them into the ground. The number 200 indicates the land where the guardrail is installed, in the cases considered by the present invention. [0075] FIG. 1b represents the same guardrail shown in FIG. 1a, but it is seen in a section orthogonal to the direction of the road.

[0076] The numbers indicate the same elements as in FIG. 1a. FIG. 1b also allows viewing of a spacer element between the upright 110 and the horizontal blockout bar 130. Said spacer element is indicated with the number 120, it has the main function of connecting the horizontal blockout bar 130 with the upright 110, and plays an important role in determining the performance of the guardrail as a whole.

[0077] Another feature, which can be appreciated from the view of FIG. 1b, is the profile of the horizontal blockout bar 130. This profile is the result of a long evolutionary process and has the advantage of ensuring an excellent compromise between mechanical performance and costs. [0078] It has already been stated that the mechanical performance of road safety barriers according to the prior art are satisfactory when they can operate in nominal conditions, because only in such conditions all the parts of the guardrail system (meaning all its component parts briefly summarized with the help of FIG. 1) work according to the design specifications when an accident occurs and the barrier is subjected to strong impacts. The nominal conditions are those that correspond to the test conditions during the so-called crash-tests.

[0079] There are various ways in which the performance of a guardrail can be tested: ranging from tests carried out in the laboratory to real tests in which a true vehicle simulates an accident and hits the guardrail. The tests performed by simulations with real vehicles are certainly the most significant, as they clearly show whether the guardrail performs its main function, which is the containment of a vehicle that is getting out of the road and stops its run in a point that minimizes the dangerous consequences of a simulated accident. This containment function always requires the complete dissipation of the kinetic energy of the vehicle involved in the accident, and this dissipation can occur in many ways: through the plastic deformation of the guardrail, or through the breaking of parts thereof. In some cases it is required that the guardrail does not detach from the ground where it is installed, while in other cases, some uprights may also detach from the ground and the containment takes place due to the holding of the horizontal blockout bar which remains attached to a plurality of uprights, some of which, when stressed by an impact of a mass having a reduced momentum, do not detach from the ground.

[0080] Ultimately, the optimal guardrail is the one that performs its function in the best possible way, and its behavior depends not only on the guardrail as such, but also on the type of road and the characteristics of the ground on which it is fixed to the ground. Finally, in FIG. 1b, above the ground 200 the road surface is also represented, indicated with the number 210, which typically consists of a layer of asphalt with a thickness of about ten centimeters. [0081] FIG. 2 illustrates the behavior of a guardrail installed in the ground on the road quay, as occurs in the vast majority of real cases. In fact, in the majority of real installations the uprights 110 of a guardrail are simply driven into the ground 200 without particular attention to the characteristics of this ground 200. Therefore, when the guardrail is hit by an impact force, indicated in FIG. 2 with the number 400, the stiffness of the road quay is often modest, typically it is not sufficient to keep vertical the upright 110, which does not deform and typically rotates as indicated in FIG. 2 (in which the rotated position of the upright 110 is represented with a dashed line). [0082] FIG. 3 instead shows a detail of a road equipped with a safety barrier according to the teachings of the invention. Differently from FIG. 2, in which the characteristics of the ground 200 were not substantially relevant (as they were not adequately taken into account for the installation of the guardrail), the ground is here depicted in greater detail. In fact, the number 201 indicates an area of land with characteristics different from the generic soil 200. In fact, the roadway on which a road is built, normally (practically always) undergoes a stabilization treatment by compacting and pressing the terrain on which the road surface is then spread. In fact, a so-called road substrate (or roadbed) is always created, whose depth is of the order of one meter (generally the roadbed is designed according to the geological characteristics of the terrain on which the road is built). Said road substrate 201 is essential, and serves to prevent subsidence phenomena of the road when it is loaded with the weight generated by vehicular traffic. Being a treated terrain, said road substrate 201 has known compactness characteristics, generally very good, because, as said, it is a terrain which must not deform under the weight of the vehicles passing on the road. Said road substrate 201 is obviously under the road surface, always indicated with the number 210; certainly, a part of terrain treated as the road substrate also extends towards the roadside, but its characteristics along the edges are certainly not as controlled as those below the road surface, and they are somehow affected by the characteristics of the surrounding terrain 200.

[0083] Another feature of the road substrate 201 is that (at least in roads at the state-of-the-art) it is homogeneous and should not host the presence of underground utilities (e.g. ducts or pipes) which should therefore be located below it.

[0084] The road substrate 201 therefore represents the ideal ground for anchoring the uprights 110 for the installation of safety barriers. Anchors of this type are known, for example from patent application no. PCT/162019/050262-Reinforcement element for fixing at the base, in ground, the uprights of roadside safety barriers, or from WO 2019/008525 A1-Device for anchoring safety road barriers poles to the ground (both already mentioned previously); however, in the known solutions some problems remain unsolved, such as the control of the mechanical performance of the guardrail, and its consequent behavior in the event of accidents, and the installation and maintenance problems, which are very onerous in the known solutions.

[0085] With reference to the mechanical performance, the trick taught in the present invention consists in the particular composition of the anchoring system, which must be composed of several parts, among which at least the three parts listed below must be present: [0086] 1. a system of vertical plates, indicated with the number 153, [0087] 2. a connecting tie rod, indicated with the number 152, [0088] 3. a junction element, indicated by the number 151.

[0089] Said system of vertical plates 153 is designed to be infixed vertically in the road substrate 201, where this is more compact, in an area below the road surface 210, possibly not too close to the edge of the road.

[0090] The infixion must take place so that its upper part remains near the upper limit of the road substrate 201 and does not cross it completely downwards, so as to minimize the risk of breaking any underground services during the infixion maneuver (remember that the underground services are normally made to pass under the road substrate). Furthermore, they must not protrude excessively above the road substrate 201, in order not to interfere with the remaking of the above road surface 210 which, from time to time, are carried out for the road maintenance.

[0091] Another characteristic of said system of vertical plates 153 (not clearly visible in FIG. 3) is that it is preferable that it has a thin cross section or, in any case, a very small section surface. A preferred conformation of the section of said system of vertical plates 153 is a cross shape. This feature, as will also be clarified later, is functional to the optimization of installation and maintenance operations.

[0092] Said connecting tie rod 152 is an element which works in tension being connected to said system of vertical plates 153 on one side and to an upright 110 on the other, even if, as will be clarified below, the connection with the upright 110 is not a direct connection. The function of said connecting tie rod 152 is to hold the upright 110 to which it is connected in the installation position, when the latter is stressed by an impact force, again indicated with the number 400, and coming from the road.

[0093] The junction between an upright 110 and a connecting tie rod 152, as already mentioned, is not a direct junction: the teachings of the present invention provide that it is implemented through said junction element 151. The functions of said junction element 151 are more than one: in fact, in addition to guaranteeing the junction between an upright 110 and a connecting tie rod 152, it allows to use uprights of very simple manufacture, such as those typically used in implementations according to the known art, which can be installed by driving through the use of a pile-driving machine, and which do not require particular conformations to hook onto said connecting tie rod 152.

[0094] Furthermore, and this is perhaps the most important characteristic of said junction element 151, it is an element of rather limited dimensions which is located near the base of the uprights 110, in an area not covered by the road surface (so that the maintenance operations are easy), and which can be sized to break when stressed by predetermined forces.

[0095] Basically, said junction element 151 must break before said connecting tie rod 152 breaks and before said system of vertical plates 153 moves due to a particularly high impact force 400 which, acting on the upright 110 towards the outside the road could drag the whole system of vertical plates 153.

[0096] Not only that, the programmed breakage of said junction element 151 can be decided, according to the case, so as to hold the upright 110 in position to determining the deformation of the upright 110 at its base, or it can be sized to break before this deformation happens, letting the post 110 rotate without deforming, or deforming only to a small extent. It is clear that when said junction element 151 is broken, the connection between the vertical plate system 153 and the upright 110 is also lost.

[0097] In short, it is possible to concentrate on said junction element 151, all the adjustments on the mechanical performances that are intended to be obtained with regard to the behavior of a guardrail in the event of an impact.

[0098] It is also emphasized that, in addition to regulating the mechanical performance of the guardrail, the use of a junction element 151, with a programmed and predetermined break, allows to preserve the integrity of the roadway in the event of particularly violent accidents that involve heavy vehicles, avoiding that the impact forces may be such that the system of vertical plates 153 can be torn off the road substrate.

[0099] Said junction element 151 can be made according to many variations. In fact, it can be a simple horseshoe-shaped element that wraps the upright 110 made with a thickness such as to give it the desired resistance, or it can be assembled with a higher resistance part completed with a lower resistance bar, closed or hooked to the connecting tie rod 152, by means of screws or pins with programmed break. In short, what is important is that said junction element 151 wraps around the base of the upright 110 and has a predefined strength, so that it breaks when a predetermined stress is reached, or it never breaks before the upright is bend over.

[0100] FIG. 4a shows an example of implementation of a junction element according to the invention which has proved effective in the context of some crash tests. The junction element presented in FIG. 4 includes: [0101] a U-shaped element, indicated with the number 151.1, whose size is suitable for wrapping a guardrail upright; [0102] a bar, indicated with the number 151.3, designed to close the element 151.1 in the shape of a U, hooking onto its two ends; and [0103] a pair of screws, indicated with number 151.2, which are used to fix said bar 151.3 to said element 151.1 in the shape of a U.

[0104] The junction element thus composed is very simple. Its shape allows the use of normal uprights designed to be infixed in ground, which, when the guardrail is installed, are inserted into the concavity of the U shaped element 151.1.

[0105] Bar 151.3 allows to install the overall system by wrapping the uprights of the guardrail even if the guardrail itself is already assembled. Finally, the screws 151.2 allow you to close the junction element 151 as a whole.

[0106] In a variant very similar to that shown in FIG. 4a, the screws can be replaced by two nuts that are screwed onto the ends of the U-shaped element 151.1, suitably threaded. In addition to the closing function of the junction element 151, these screws 151.2 (or the equivalent nuts) can also act as a mechanism for tensioning the connecting tie rod 152 after installation.

[0107] As mentioned, an essential feature of said junction element 151 is given by the fact that it must be able to split (thus opening the ring that holds the base of the upright 110) by effect of a predetermined and controllable stress force.

[0108] The programmed break can be obtained by acting on the dimensioning of the thickness of the material with which said U shaped element 151.1 is made, or by acting on the choice of screws 151.2, or on the tightness of their thread.

[0109] The programmable break can also be adjusted in the field, and very easily, for example by making a hole on said bar 151.3 as shown in FIG. 4, where a hole indicated with the number 151.4 is visible. Evidently, in correspondence with the hole a weak point of said bar 151.3 is determined, which will break precisely in that zone when stressed by a strong traction which tends to widen said junction element 151; and the force necessary to break will be less the larger the hole. In this way, by making holes of different sizes on the bar 151.3, it is possible to adjust the programmed breakage of the junction element 151. Furthermore, said junction element 151 is designed to hook to said connecting tie rod 152 (shown in FIG. 3). Even this hooking arrangement can be obtained in many ways: a very simple, even banal, way is to provide a hook on the end of the connecting tie rod 152, which hooks said junction element 151 at any point.

[0110] FIG. 4b shows another embodiment of the junction element 151, also tested in experimental crash tests. FIG. 4b shows said joining element 151 in an overall view in which it is connected to a connecting tie rod 152 (in a form of implementation consisting of two metal bands), and to a system of vertical plates 153 (also this last in a form of implementation other than that previously considered, which had a cross shaped section). The junction element 151 is then shown as an enlarged detail in FIG. 4b, to highlight its simplicity: it is essentially formed by a metal bar bent in a U shape, and does not require any closing bar, since the closure around the base of the upright to which it is to be coupled is completed by the end of the connecting tie rod 152.

[0111] Breakage can be controlled: [0112] by acting on the dimensioning of the thickness of the metal bar bent to U, of which the junction element 151 is made up; [0113] or by choosing the mechanical strength of the screws with which the junction element 151 is attached to the connecting tie rod 152; [0114] finally, even in this form of implementation, weakened breakage areas can be created by making holes or incisions on the U bent metal bar, of which the junction element 151 is made.

[0115] Ultimately, the junction element 151 shown in FIGS. 4a and 4b really represents only few of the many forms of implementation with which it can be implemented, provided that the few essential characteristics required for the implementation of the present invention are preserved; and in particular, the possibility of making it so that it breaks, by opening, stressed by a predetermined force, that it is of reduced size, and that it is designed to be mounted at the base of the guardrail uprights in an easily accessible position for its installation, maintenance or replacement. [0116] With the aid of FIG. 5, it is possible to illustrate how the present invention also offers a satisfactory solution to the installation problem: allowing both installation and maintenance in a relatively simple way, and above all with procedures that can be performed with the typical machinery that is normally supplied to operators involved with guardrail installations.

[0117] FIG. 5 shows, in a very simplified way, a road, indicated with the number 300, equipped with a safety barrier according to the teachings of the present invention. For reasons of essentiality, in FIG. 5 the barrier is installed only on one side of the road, and the proportions between the sections of the uprights and the road width are obviously unrealistic: however the purpose of the representation is only to support the description of the road as a whole, intended as a system, highlighting some problems concerning the installation of the safety barrier on the roadside, and its possible maintenance. FIG. 5 shows four uprights, indicated with the number 110, fixed on one side of the road 300. It is observed that the uprights shown in FIG. 5 are of a very common type, with C profile, and, regardless of the profile, they are of the type that can be easily installed by infixing them on the ground, using a pile-driving machine.

[0118] Each of said uprights 110 is surrounded by a joining element 151.

[0119] Well inside the street 300, the shapes of the section of three systems of vertical plates are highlighted, again indicated with the number 153.

[0120] Finally, each upright 110, through the junction element 151 and a connecting tie rod 152 is connected to at least one system of vertical plates 153.

[0121] Although a simple connection scheme is practicable, in which each upright 110 is connected to a single system of vertical plates 153, it can be observed that there may be some convenience in connecting each upright 110 to a pair, or even to three, vertical plate systems. In this way, when an upright 110 is hit by an impact coming from inside the road, and which would therefore tend to push the upright towards the outside of the road itself, the resistance to this movement would be exerted not only by the resistance of a single system of vertical plates 153, but by the strength of two, or three of these. In the example of FIG. 5, the vertical plate systems 153 are placed in an intermediate position between two uprights 110, furthermore each upright 110 is connected to the two vertical plate systems 153 which are located at its sides, as well as each system of vertical plates 153 is connected to the two uprights 110 which are at its sides. This connection scheme has the advantage of being very simple and, in addition, it has the advantage that, when two contiguous uprights are hit simultaneously by an impact that would tend to move them away from the road, the two reaction forces exerted on a system of vertical plates 153, and transmitted by the two connecting tie rods 152 connected to this vertical plate system 153, have a component that tends to cancel itself out, and therefore does not contribute to a potential displacement of the vertical plate system itself which, as explained, must remain stationary in its position even in the event of an accident. It has to be recalled that each of these connections can be made as illustrated above, with the help of FIG. 3.

[0122] Regardless of the connection scheme, which can be chained as shown in FIG. 5, or organized in another way, giving rise, once again, to many variants of implementation, what is important to highlight is that the whole system can be installed in very simple way. In particular, it is interesting to note that even the installations of elements that are to be positioned under the road surface 210 can be installed with relative ease.

[0123] In fact, an essential feature of the system of vertical plates 153 is that it has a thin horizontal section, and this allows to drive said system of vertical plates 153 into the road substrate, without removing the asphalt of the road surface, but simply by cutting it according to a shape as that of the vertical plate system 153. In the case of the example shown in FIG. 5, the cross-sectional shape of the vertical plate system 153 is a cross shape, which represents one of the preferred implementation forms for its effectiveness, and for its simplicity.

[0124] Once the correct shape has been cut, the system of vertical plates 153 is driven into the road substrate by means of a pile-driving machine commonly supplied to operators in the sector.

[0125] The connecting tie rod 151 also has a thin shape that allows it to be inserted under the road surface through a cut in it.

[0126] It is noted that the cutting of the road surface is a relatively simple operation, which does not require special tools (it is commonly found among the equipment supplied to operators in the sector, like pile-driving machines).

[0127] Among the road surface restoration operations, one of the simplest is precisely the sealing of the cuts. Therefore, through this sealing operation, the road surface is restored and made accessible so that the road can be traveled.

[0128] The installation operations described above can also take place if the vertical plate system 153 has a section with enlargements (for example in the center). In this case, in addition to cutting the asphalt, it is also necessary to carry out a core drill to remove a small part of the road surface in order to make a hole in the road surface itself, to accommodate any enlargement of the vertical plate system 153. It is here observed that the core drilling of asphalt for the removal of small asphalt layers is a simple operation and can be carried out with generic equipment, therefore there are no problems with respect to the general objectives of the invention which aim to seek a solution that can be implemented by a large multitude operators without placing requirements on the instrumentation they must have at their disposal, posing potential discrimination in the choice of operators to whom to assign the work.

[0129] In this latter case, the restoration of the road surface is slightly more complex, because we do not have to limit ourselves to sealing a cut, but it is also necessary to plug the hole made with the coring; however, for small holes, even this maneuver is relatively simple and can be performed with cold worked material.

[0130] It is clear that the restoration of the road surface is important to quickly restore the viability of the road 300, but, obviously, the asphalt paving remains marked by the interventions carried out. However, at the first maintenance of the asphalt resurfacing, every trace disappears, and the buried underground system is designed to last over time.

[0131] At this point, it is reiterated that both said vertical plate systems 153 and said connecting tie rods 152, when installed, are in contact with the road substrate 201 (the vertical plate system 153 is immersed in the road substrate), and possibly immersed only in a small part in the bottom part of the road surface 210, so that even maintenance which requires the removal of the road surface, for the subsequent reconstruction, can be carried out without interfering with the system described.

[0132] Once the vertical plate systems 153 and the connecting tie rods 152 have been installed, the ends of the connecting tie rods 152 which are close to the uprights 110 must be connected to the uprights themselves: as already explained, this occurs through the junction elements 151.

[0133] From the installation point of view, it is important to observe how this coupling between the connecting tie rods 152 and the junction elements 151 can take place indifferently even if the uprights 110 are installed or before installing them. In this second case, the junction elements 151 are placed on the ground so that they surround the point where the upright 110 is to be infixed, and the latter can be driven in at a later time, as normally occurs with a pile driver. The installation is then completed by tensioning the connecting tie rod: this maneuver can also take place with one of the many known tensioning systems, for example with a screw system positioned on the junction element.

[0134] This installation sequence, that is the fixing to the ground of the uprights 110 of the guardrail after the installation of the vertical plate systems 153 and the connecting tie rods 152, is typical of the installations carried out during the construction of new roads, in which the complete road, with its mantle, is normally completed before the installation of the guardrails: in this case it is obviously convenient to install the vertical plate systems 153 and the connecting tie rods 152 as soon as the road substrate 201 is ready, before laying the road surface 210 (thus avoiding unnecessary cuts).

[0135] On the other hand, when it is necessary to reinforce an existing safety barrier, which is present on a complete road, the junction elements 151 must be coupled to the already fixed uprights 110: for this reason it is necessary that they are composed of several pieces that allow their opening, to wrap the base of the uprights 110, and a subsequent closing, around the base of the uprights 110, ending with a tensioning operation of the connecting tie rods, obviously pre-installed as already explained above.

[0136] A final observation, about maintenance aspects, concerns the access to the connecting tie rods 152, or to the vertical plate systems 153, when these elements are under a road surface 210, which has been redone after the installation of these elements, and therefore the signs of the cuts are not visible. Well, being the elements in question, in general, metal elements that are located at a depth of the order of ten centimeters, it is easy to find them using a metal detector, which is, for sure, able to identify the precise position where to make a cut for reaching the elements to be maintained.

Concluding Remarks

[0137] In general, as seen from the previous description, the road system, according to the present invention, lends itself to numerous implementation variants, as well as the method to implement it, can be put into practice with some variants, provided that the essential steps indicated in the attached claims are maintained.

[0138] The provided description already highlights how many variations are possible. In fact, the possible forms for making the vertical plate systems 153 are innumerable, as well as the junction elements 151 and the connecting tie rods 152 can be implemented in many ways to connect them to the uprights 110 for guardrails.

[0139] With strict reference to the geometric shape of said vertical plate systems 153, it is worth underlining how the plates can assume all possible geometric shapes. All these variations of shape show that it is not the shape of the plates that is a characterizing prerogative, but rather the fact that these plates are a functional element designed in order to exploit a greater quantity of earth to increase the infixion strength of an upright for guardrail 110, when hit by a violent impact.

[0140] Regarding their shape, the only feature that seems recommendable is that they are flat, so that they can be driven into the road substrate 201 by inserting them into straight cuts and therefore easy to be done. It is evident that if these plates were obtained on wavy metal plates, the cutting of the road surface 210 to drive them into the road substrate 201 should also have a wavy shape, causing a useless installation difficulty.

[0141] Possible further variants may also depend on technological aspects concerning the individual components of the system, such as any additional consolidation and stiffening subsystems, but also on the materials that can be used to make each single part of the system.

[0142] These variants can offer further advantages over those already mentioned, and can be implemented by the man skilled in the art without thereby departing from the scope of the invention as emerges from the present description and the attached claims.

[0143] Furthermore, the invention itself can be implemented in a minimal or superabundant way, for example with plate systems composed of a single plate, or with a number of plates greater than two, and arranged in various ways and in different directions: even if the solution with two plates arranged in a cross (therefore with a four-branch system) appears to be the preferred form of implementation for simplicity of construction and installation (making two orthogonal cuts seems the simplest thing to do).