MXPA99007794A - Safety barrier terminal for motorway guard-rail - Google Patents

Abstract

A safety terminal (10) comprises a number of longitudinal segments (12a, 12b, 12c...) provided with elongated slots and fastened together in such a way as to be capable of sliding longitudinally over one another, with consequent absorption of energy, each segment being supported by an upright or post (18a, 18b,...) made up of two half-posts connected together by breakable means having a preset breaking strength, the bottom half-post being burried in the ground;the said terminal moreover comprises a cable (30) between the bottom half-post (18') of the end post (18) and the top half-post (18") of the adjacent post, the said cable (30) comprising a breakable plate having a preset breaking strength. Preferably the headpiece of the terminal comprises a restraining frame extended from a plate orthogonal to the longitudinal extent of the terminal. The new terminal enables good absorption of impact energy of a possible vehicle, whilst at the same time requiring reasonable costs for restoring.

Description

SECURITY BARRIER TERMINAL FOR CONTAINMENT BARRIER IN HIGHWAYS DESCRIPTIVE MEMORY This invention relates to the field of safety barriers, or containment barriers, for use on roads or highways. The security barriers type "containment barriers" are known, and comprise a longitudinal, horizontal, or dormant member, which may consist of a strip of corrugated steel sheet mounted on poles or supports. These safety barriers present very safe and predictable results in the event that a vehicle is impacted at the path angles that are not very wide with respect to the longitudinal extent of the barrier. However, for reasons of comfortable access to the road, or for other reasons, it is unthinkable to build a continuous protection barrier along the entire road between the starting and finishing points of the road itself. Consequently, the protection barrier will inevitably be built in more or less long sections that have terminal portions. Although the statistics have shown a quite satisfactory behavior of the protection barrier in case of impact against an intermediate portion of it, they have also shown an increasing incidence of vehicles that are impacted against the ends or terminals of the barrier, with consequences that they are almost always serious or tragic because the hardness of the barrier is very high in the longitudinal direction, and because of the high kinetic energy, caused by the high speed of the vehicle. In addition, the height of the ends can be dangerous. Therefore, recently more attention has been paid to the problem of shock absorption in the event of a frontal impact against a safety barrier. A widely adopted solution consists of placing the terminal segment of the barrier inclined downwards in the direction of the earth; this prevents a vehicle from colliding head-on with one end of the barrier at a dangerous height; however, it can cause the vehicle to lift off the ground and even reach dangerous heights. Other currently known solutions comprise that the barrier terminals can absorb energy by compaction, said terminals consist of several barrier segments that are secured to one another in longitudinal succession by means of calibrated bolts coupled in grooves in the segments; the barrier is double by at least in the terminal portion, and a wooden post supports each pair of parallel segments of the protective barrier, the post has a hole passed at a certain height, in such a way that it can withstand transverse impacts to the barrier , as well as breaking when suffering an impact of pre-established magnitude longitudinal to the barrier. The impact of a vehicle against the terminal causes the screws and poles to break, and the sections to overlap each other. The known terminals of this type are widely used in some states of the United States, however, it has a disadvantage, since a particular type of wood that has a high price must be used. The cost of such barriers is relatively high even when the wood is available locally; if it had to be transported, as it is done to other areas, the cost of the poles would be prohibitive, also considering that it is not possible to repair them after an impact. In addition, in any case the hardness of the poles is excessive and relatively dangerous. The state-of-the-art technology also includes a highway safety barrier made of a single strip of a curved section in the terminal where a wide head fitted with a roller system is mounted. In the case of collision of a vehicle against the terminal, ie against the head of the terminal, this header slides along the metal strip, flattening it as it passes, the absorption of energy is provided by the deformation of the metal strip . A variant of this system comprises a terminal with a header equipped with special knives, which in the case of impact of a vehicle runs along the protective barrier in such a way that the knives cut the protective barrier in thin parts. In this case, energy absorption is provided by longitudinal cutting of the metal strip. These last two systems have the disadvantage that they are difficult to calibrate, besides being expensive. The cutting-edge technology also includes shock attenuators. These are devices that are placed to protect a particular object that is considered dangerous or that is in a dangerous position for transit. Shock attenuators are different from terminals because they have better performance and higher costs. In fact, a terminal works only as long as it is connected to a safety barrier, while a shock attenuator can operate even when it is isolated, protecting a relatively narrow dangerous obstacle, such as a bridge stack or an end of a low wall. The object of this invention is to create a terminal for motorway protection barriers that allows a good absorption of energy in the event of impact, a good retention of the vehicle, and thus provide a good level of safety, and at the same time can be made and repair with acceptable costs. These objectives have been achieved with a terminal that is described in appended claim 1. In addition, new features that can be used in the subsequent claims are described. The new terminal comprises a longitudinally extending strip made of a number of barrier segments provided with elongated slots in which screws are attached to join the segments by screwing them with a calibrated tightening torque.; it also comprises a header at the terminal applied in the end segment; each segment is mounted on a stand or pole that is made of two half poles; a substantial portion of the height of the lower post is placed within the earth, and the upper portion is mounted on the bottom by a predictably breakable transverse pin, i.e., a pin having a predetermined breaking strength, and preferably having a groove that engages with a pin of the bottom half post. According to another characteristic of the invention, at least between the lower half-post, which supports the terminal segment and / or the head-end, and the adjacent upper pole-post, a connecting rod is mounted, which consists longitudinally of a cross section. weakened with a pre-established or predictable breaking force. According to another feature, the head comprises a plate that is transverse to the longitudinal extension of the barrier and has a protruding frame to retain the vehicle, as well as to prevent a vehicle hitting the terminal from sliding laterally without power Take advantage of the energy absorption provided by the terminal. According to another aspect of this invention, the support or post made of two half poles, a substantial part of the height of the lower one is placed inside the earth, and the upper one is mounted on the lower part by means of a restraint that can be released predictably, A wide variety of road safety barriers can be used, including highway safety barriers of any suitable design. In this manner, the breakable post of this invention has no restriction for use with a particular protection barrier that is shown in the accompanying drawings. The new terminal allows a good absorption of energy, and therefore a considerable degree of safety, for a vehicle in the event that the latter is impacted against the terminal with a substantial component of force parallel to the longitudinal extension of the barrier or protection barrier. In addition, it has a relatively reasonable production and installation cost, and can be repaired quickly with reasonable costs. An exemplary exemplary non-restrictive embodiment of the invention will now be described with reference to the accompanying drawings, in which: Figure 1 is an enlarged side view, on a reduced scale, of a safety barrier terminal of a motorway conforming to the present invention. Figure 2 is a top plan view with respect to Figure 1; Figure 3 is a cross-sectional view according to a plane indicated with 3-3 of Figure 1; Figure 4 is a sectional view; cross section according to a plane indicated by 4-4 in Figure 1. Figure 5 is a view of an end header according to the arrow referred to with number 5 in Figure 1. Figure 6 shows an elongated detail of Figure 1. Figure 7 is a cross-sectional view according to a plane indicated with 7-7 in Figure 6. Figure 8 is a cross-sectional view according to a plane shown with 8-8 in Figure 6.SiZ Figure 9 is a full scale representation of a predictably breakable plate, i.e. a plate having a predetermined breaking strength, of a barrier connecting rod. Figure 10 is a top plan view with respect to Figure 9. Figure 11 is an elongated side view of a terminal header mounted on an end segment of the barrier. Figure 12 is a top plan view with respect to Figure 11. The security terminal for the highway security barriers is indicated complete with reference 10 in the figures and is suitable for application to the ends of the security barriers of road of the type of protection barrier, which comprises one or more strips of corrugated metal sheet supported by supports or posts. The terminal 10 basically contains some segments 12 of elastic metal strips, each of which has the number 12a, 12b, 12c, ... respectively, starting from the end segment 12a. Each of the segments 12a, 12b, 12c as can be seen in Figures 3, 11 and 12, comprises a corrugated metal strip with double corrugation, with longitudinal grooves or slots aligned in 2 parallel rows, with numbers 13 and 14 respectively. According to the features of this invention, the grooves 13 of one row and the grooves 14 of the other row are reciprocally mutually in the longitudinal direction. In the area where the edge portions of the segments overlap, the segments of the corrugated section barrier, 12a, 12b, 12c are held together in a manner known per se by bolts 15. The bolts are tightened with a tightening torque. calibrated, while the metal sheet makes a bridge between each of the grooves and the next one is made of such a that it can be crushed with a pre-established force applied when the bolts pass through them. In each segment, 12a, 12b, 12c, etc., a support or support post is respectively provided with the numbers 18a, 18b, 18c, etc., while the reference 18 indicates an end support that supports a header 20 applied to a extreme segment 12a. Each support or post comprises a lower pole half and a top half pole, respectively with reference 18 'and 18"for the post 18, 18'a and 18" a for the post 18a, and in the same way 18'by 18"b for post 18b and 18'c and 18" c for post 18c. The lower poles means have a lower pin 16 or pin and, placed on top, a predictably breakable pin 17, ie a pin having a predetermined breaking strength, where the pole half engages. higher. In particular, the pin 17 passes through the registration holes of the lower half post and of the upper upper post, while the rod 16 engages in a cavity 16 'of the upper middle post. In the embodiment described, the lower half post is made of the section I and the upper half post of the channel section, while the reinforcements 19 are located along the flanges of the metal section forming the middle top post. . Between the first support 18 and the second support 18a extends a connecting rod 30 which is fixed with one end thereof in the lower half-post 18 'of 18 and with the other end thereof in the upper half-post 18"a. The connecting rod 30 generally comprises a cable portion, a tension device that is known per se, and preferably, comprises a predictably breakable plate, i.e., a plate having a predetermined breaking strength, generally consisting, as see in Figures 9 and 10, in a metal plate with a thin portion 33. The head or head 20 (Figures 5, 11, and 12) has an end plate having the number 22, which is substantially orthogonal to the extension longitudinal of the barrier and fastened to the end of the end segment of the metal section 12a by a lower bracket 24 and an oblique arm 25. The plate 22 comprises a restrictive projection 26 which is located around the perimeter of the plate near the periphery of the latter. The aforementioned restrictive projection has the purpose of retaining a vehicle that collides against the headrest in such a way as to avoid any lateral displacement of the vehicle that could cause it to deviate and thus not be able to take advantage of the power absorption possibilities of the terminal. security, with huge subsequent risks.

The restrictive projection generally comprises a metal sheet bent and welded to the base plate 22. As mentioned, the new protective barrier terminals or road safety barriers are assembled with the supports within the ground almost at the total height of the lower pole means 18 ', 18'a, etc., as indicated by the dotted line S in Figures 1, 3 and 4. When a vehicle collides with the terminal with a force component that is substantially longitudinal to the barrier , the energy of the impact is substantially dissipated by the force of friction between the elements 12a, 12b, etc., breaking the bridges separating the grooves of said elements, breaking the breakable plate 32, and breaking the pegs 17 of the supports. After impact, the terminal can be restored relatively eas by replacing the barrier elements 12, 12a, etc., which were deformed, by replacing the connecting rod element 30, replacing the calibrated pins 17 and repairing the upper pole means . Of course, many variations and modifications are possible. For example, the separation post described above can be used with protective barriers with other types of segments and headers. The upper half post can be formed with any suitable geometry, including a solid cross section or a rectangular channel cross section. The lower half post can also be formed with any suitable geometry, including a cross section of channel C, or a solid cross section defining a groove for the middle top post. The fastener may include a separation pin as described above, which may be formed of stainless steel, and which may use conventional fasteners, such as an elongated head and a fin pin to hold the pin in place. Other type of fasteners may be used, while allowing the upper half post to exit the slot in the lower half post when excessive back loading is applied. For example, a breakable or flexible fastener can be mounted or formed on the flanges of the lower half post to secure the upper half post so that it can be released in its vertical orientation. The described system is easy to install because the lower half post can be placed on the ground easand quickly, and then the upper half post can be put in place simply by placing it on the spike and then installing the separation pin. The separation posts can easbe repaired after a collision. Frequently, it is not required more than the replacement of the middle upper post in the vertical position on the dowel of the lower half post, and then install a new separation pin. The above description should be taken as an illustration of the preferred embodiments chosen of the invention, and not as a definition of the invention. Only the claims below, including all their equivalents, are intended to define the scope of this invention.

Claims (2)

1. NOVELTY OF THE INVENTION CLAIMS 1. - A terminal for a road safety barrier comprising: barrier segments (12a, 12b, 12c, ...) provided with slots located longitudinally one with respect to the other in a double row (13, 14), separated in each row by means of predictably breakable bridges, said barrier segments being connected by means of bolts (15) passing in said grooves, said segments are supported on breakable supports, in such a way that upon receiving an impact against said terminal with a force or a component of force or a level of energy higher than the pre-established tolerance, the aforementioned segments can slide on each other, dissipating the energy in this way, and the aforementioned supports can break; characterized in that each mentioned breakable support (18, 18a, 18b, 18c.) comprises a lower pole half and a top half pole (18", 18" a, 18"b, 18" c ...), of which the The upper pole half is constrained to the lower one by a breakable system (16, 17), and because the extreme segment (12a) carries a head (20).
2. 2. A terminal for a road safety barrier according to claim 1, further characterized in that the aforementioned breakable system comprises a breakable pin (17). 3. - A terminal for a road safety barrier according to claim 2, further characterized in that said breakable system further comprises a spigot and a surface for coupling the spike on the opposite pole means. 4. A terminal according to claim 1, further characterized in that a substantial part of the height of the lower pole means is buried in the ground. 5. A terminal for a road safety barrier according to claim 1, further characterized in that in the mentioned barrier segments the grooves are not continuous but are interrupted by breakable bridges having a predetermined breaking strength. 6. A terminal for a road safety barrier according to claim 1, further characterized in that in said barrier segments the grooves (13) of one row and the grooves (14) of the other row are longitudinally staggered one with with respect to the other. 7. A terminal for a road safety barrier according to claim 1, further characterized in that at least between a lower half post (18 ') of a support (18) and a middle upper post (18"a) from the adjacent support (18a) a breakable connecting rod (30) having a predetermined breaking resistance is extended 8.- A terminal for a road safety barrier according to claim 7, further characterized in that the said connection (30) comprises a cable portion and a breakable plate (32) having a predetermined breaking strength 9.- A terminal for a road safety barrier according to claim 1, further characterized in that said header (20) comprises an end plate (22) which is positioned substantially transverse to the longitudinal extent of the barrier and is equipped with a restrictive projection for vehicles or salient edge. (26) 10. A terminal for a road safety barrier according to claim 9, further characterized in that said retaining edge (26) extends around the perimeter of the plate (22) at a short distance. Of the same. 1 1.- A terminal for a road safety barrier comprising: a plurality of barrier segments, and a plurality of supports that support the barrier segments, characterized in that at least one of the supports comprises a lower pole means , a top half post, and a breakable system that releasably secures the top half post with the bottom post half. 12. A breakable support for a road safety barrier comprising: a lower pole half, a top half pole, and a breakable system that releasably secures the upper pole means with the lower pole half. 13. - The invention according to claim 1 1 or 12, further characterized in that the breakable system comprises a breakable pin. 14. The invention according to claim 1 or 12, further characterized in that the breakable system comprises a spike in one of the pole means and a surface for coupling the spike on the other half pole. 15. The invention according to claim 11 or 12, further characterized in that a substantial part of the height of the lower pole half is buried in the ground. 16. The invention according to claim 11 or 12, further characterized in that the lower pole means comprises an I-beam element, wherein the upper pole means comprises a channel-shaped element C, and where the C-shaped channel element is received in a groove forming the I-beam member. 17. A retaining barrier for a roadside comprising a plurality of the support posts according to claim 1. 1 or 12, and at least one barrier segment supported by the upper pole means. 18. A road safety barrier support post comprising: a lower post portion, a top post portion mounted to the upper post portion; and a fastener releasably retaining the upper post in a chosen initial position with respect to the position of the lower post. 19. The invention according to claim 18, further characterized in that the fastener comprises a breakable pin. 20. The invention according to claim 18, further characterized in that the lower post portion comprises a slot receiving the upper post portion, and wherein the lower post portion comprises a pivot oriented transversely to the slot, said opening The slot portion is located to one side of the lower post portion to allow the portion of the upper post portion to move out of the slot. 21. The invention according to claim 20, further characterized in that the lower pole portion comprises a core and two separate parallel flanges that join the groove, wherein the core protects the upper pole portion against the pivoting towards the core. . 22. The invention according to claim 20, further characterized in that the fastener comprises a breakable pin extending along the slot and the upper pole portion. 23. The invention according to claim 20, further characterized in that the pivot comprises a spigot extending through the slot, and wherein the lower post portion comprises a spigot engagement surface. 24. The invention according to claim 18, further characterized in that the lower post portion comprises an I-shaped beam element, wherein the upper post portion comprises a C-shaped channel element, and wherein the element of channel in the form of C is received in a groove forming the beam element in the form of I. 25.- A protective barrier for roads edge comprising a plurality of support posts in accordance with claim 18 or 20, and at least one barrier supported by the upper pole portions. 26. The invention according to claim 18 or 20, further characterized in that at least a substantial part of the height of the lower post portions are buried in the ground.