Patent Application
20200354908
The present disclosure relates to a surface mount security barrier, in particular to a surface mount security barrier for preventing or retarding vehicular passage.
With the increasing incidence of terror attacks using the weaponization of vehicles by driving them at crowded pedestrian areas, there is an increasing need for barriers that prevent or hamper vehicular passage.
In general, security barriers, or crash barriers, the main purpose of which is to prevent the passage of vehicles, are widely known in the art and have many applications. Common applications are for bordering dangerous sections of roads, providing a central separation between lanes of traffic moving in opposite directions, and around secure areas, for example around the entrance to airports or the like.
Such barriers generally include some form of underground footing which is either integral with an above ground section of the barrier, or to which an above ground section of the barrier is attached. While these provide an adequate solution for permanent areas of risk where the cost and disruption of installing them is justified, they do not provide a good solution where a temporary measure is needed. Examples of where a temporary measure may be needed are at intended permanent sites prior to the installation of a permanent solution and at seasonal or short-term events, for example music festivals, Christmas markets or the like.
Some solutions such as concrete blocks which can be manoeuvred into location are used, however these are generally not effective against anything apart from slow moving light weight vehicles and do not meet the requirements of standards such as the BSI IWA14.2013 collision test, in particular existing such blocks when impacted by, for example a 7 tonne truck travelling at 48 kph (30 mph) will be propelled considerable distances at high speed. In a crowded environment such as a Christmas market or a music festival these bollards can cause significant damage. In addition, if these exiting blocks are hit on the corner they tend to spin and are ineffective at hindering the passage of a vehicle.
It is an aim of the present invention to provide an effective security barrier that can easily be placed on top of the existing ground surface at a required location without the need for any excavation or specific surface preparation.
According to an aspect of the present invention there is provided a surface mount security barrier comprising: a plurality of barrier islands each comprising: a concrete crash block having at least one pair of opposing side faces; external fixing elements at said opposing side faces of the concrete crash block, and one or more load transfer element embedded internally within said concrete crash block; and one or more attachments extending between external fixing elements of adjacent barrier islands. Under load, the load transfer elements transfer load through the concrete crash block from the external fixing elements on one side of said concrete crash block to the external fixing elements on the opposing side of said concrete crash block.
The load transfer elements may be configured such that, when the security barrier is subject to sufficient impact to create tension in said attachments, the load transfer elements transfer load between external fixing elements of a barrier island without imparting a significant tensile load on the concrete crash block. By without imparting a significant tensile load on the concrete crash block what is meant is that, although under impact there will always be some tensile loading on the concrete crash block, the concrete crash block is not required to bear the full load between the external fixing elements in tension, as the tensile load is taken up in the load transfer elements.
A longitudinal axis of each said one or more load transfer element may be substantially parallel to the longitudinal axis of the security barrier. Under impact the load of impact on one barrier island is transferred through the attachments to an adjacent barrier island. As the load transfer elements transfer the load of impact between the attachments the load is transferred through the concrete crash blocks without the concrete blocks assuming any significant tensile loading. As concrete has a relatively low tensile strength this enables the load under impact to be transferred between adjacent barrier islands without risking failure of the concrete crash blocks.
In an embodiment the load transfer elements are attached at either end to a said external fixing element. In this manner the load can be transferred directly as a tensile load through the load transfer element. In an arrangement the load transfer element may comprise one or more nylon strap. In another arrangement the load transfer element may comprise a steel or composite element.
In an arrangement the at least one pair of opposing side faces comprises two pairs of opposing side faces, and the one or more load transfer element extends between external fixing elements on opposing side faces of each pair. In this manner barrier islands maybe arranged perpendicularly to one another such that the barrier can turn a corner.
The attachments may be flexible attachments which, in use, may extend along the ground between said adjacent barrier islands. In this manner the barrier can be arranged to allow pedestrians or small vehicles, e.g. bicycles or motorbikes, to pass between adjacent barrier islands. Under impact, however, the flexible attachments will still provide the transfer of load between adjacent barrier islands.
Optionally the opposing side faces have at least one recess therein and an external fixing element is located in the recess. The opposing side faces may each have two recesses therein and an external fixing element located in each said recess. The recesses may extend vertically along the opposing side faces from a lower edge thereof.
In one arrangement each recess may comprise a U-channel, which may be steel, extending vertically along a said opposing side face from a lower edge thereof, the U-channel embedded in said concrete crash block and opening onto its side face. The external fixing element can extend through the U-channel at a position above said lower edge. In this manner the U-channel provides a reinforced channel extending from the external fixing element towards the ground so that the flexible attachment can extend from the external fixing element, along the reinforced channel to the lower edge, substantially along the ground between adjacent barrier islands, up the opposing U-channel and to the respective external fixing element on the adjacent barrier island.
A pin may be provided that extends across the recess substantially adjacent the lower edge.
A hole can be provided in the U channel and a tube can extend therefrom such that the pin is slidable in the tube through the hole. The flexible attachment may pass behind the pin, thereby retaining it adjacent the lower edge of the side face.
A cover plate can be provided that extends over the recess or recesses. In this way, in use, the external fixing element, and the flexible attachment within the recess, are both hidden from view and protected.
The flexible attachment may comprise any suitable material, in one arrangement it may comprise one or more nylon strap.
A rebar cage may be embedded within the concrete crash block below the surface thereof.
In one embodiment a barrier island may comprise a plurality of feet extending from a bottom surface thereof. Optionally, the feet may be formed as part of the rebar cage and when the barrier island is formed, the feet may project outwardly from a lower surface thereof. The feet may project from the lower surface of the barrier island for a distance of 1 mm to 10 mm. In use, when placed on a hard surface, due to the weight of the barrier island, the feed will, under impact, act as “teeth” and provide very high-pressure contact points which, if the barrier island moves as a result of an impact, will dig into the surface on which it is situated, further impeding the movement of the barrier island.
In an alternative arrangement the security barrier may further comprise an anti-skid plate associated with each barrier island, wherein the anti-skid plate has a plurality of metal feet extending downwardly therefrom. The anti-skid plates may comprise a steel tray in which the associated barrier island is located. The tray may have upstanding sides within which the associated barrier island fits, and a plurality of feet extending downwardly from the plate at a distance of 1 mm to 10 mm. When located in the anti-skid plate the associated barrier island may be retained therein by the application of a grout between the barrier island and the anti-skid plate. Under impact the anti-skid plate will function in the same manner as the projecting feed described above.
In one arrangement the security barrier may comprising metallic ballast within said concrete crash block. This increases the density of the crash block such that its mass can be increased. The mass of the barrier island may be in the range of 7.5 tonnes to 8.5 tonnes and may comprise at least 5.5 tonnes of ballast.
In an embodiment the barrier may further comprise one or more fence post holes extending downwardly into a top surface of each barrier island and/or one or more security post footing extending downwardly into a top surface thereof, said security post footing for receiving, in use, a security post. A fence post may be located in one or more of the fence post holes in adjacent barrier islands, and at least one fence panel may be attached to fence posts of said adjacent barrier islands. Alternatively, or in addition, at least one openable gate attached to said fence posts of adjacent barrier islands. A spring steel security post may be located in the security post footing of adjacent barrier islands to which a further security barrier comprising either one or more flexible barrier or a rigid barrier may be attached so that it extends between the security posts of said adjacent barrier islands. The flexible or rigid barrier may either be permanently attached to said security posts, or be releasable from said security posts to create an openable barrier.
Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.
One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
A security barrier, also known as a crash barrier, in accordance with example embodiments of the present invention is described herein with reference to the accompanying
With reference to
In the embodiments of
As can be seen in
As shown the flexible attachments 14 pass down the side of the barrier islands 12 and across the space between them substantially aligned with the lower surface thereof. In use this means that the flexible attachments 14 run substantially along the surface on which the security barrier 10 is mounted. This allows easy and unimpeded pedestrian access between the barrier islands 12. This allows for the free movement of people past the security barrier 10 while maintaining a high degree of protection against vehicular penetration. Although not shown it will be appreciated that the flexible attachments 14 may be covered during use to prevent them from being a trip hazard. Covers, such as those used to cover cabling that needs to be run along the ground for outdoor events, to eliminate trip hazards, is well known. Where the surface mount security barrier 10 is to be installed in a permanent or semi-permanent location the flexible attachments 14 maybe run between the barrier islands 12 slightly below the surface level so as to eliminate the trip hazard, for example a thin layer of tarmacadam, gravel or other suitable surfacing material that will easily allow the flexible attachment 14 to lift if the security barrier 10 is impacted, could be used.
Under impact, if hit square on, the barrier island will absorb a relatively large impact, however if the impact is too great then a single barrier island 12 without the flexible attachments 14 may skid along the ground as the momentum of the vehicle is transferred to the barrier island. Furthermore, if someone is trying to penetrate a row of bollards with a vehicle they will often aim for the gap between the bollards, even if it is not sufficiently large enough for the vehicle to pass. With surface mount barriers, e.g. rectangular pieces of concrete, the impact occurring on the corners of adjacent ones tends to cause them to spin and move, often allowing the vehicle to pass substantially unimpeded in the created space. In the present invention, when struck in such a manner, the barrier islands 12 may start to spin but as they do so the flexible attachments 14 will pull tight thereby both arresting spin and preventing the gap exceeding the length of the flexible attachments 14. In addition, when the flexible attachments 14 pull tight the load is transferred through each barrier island 12 to adjacent ones, via the flexible attachments 14, via the internal structure of the barrier islands 12 in such a manner as to prevent the full load transfer being applied to the cast concrete as a tensile load thereon.
Referring to
The concrete crash block 17 has at least one pair of opposing side faces, which are also opposing side faces 18, 20 (See
As shown, the longitudinal axis of each load transfer element 24 is substantially parallel to the longitudinal axis of the security barrier 10 and is also substantially perpendicular to a direction of impact protection of the security barrier. By direction of impact protection it is meant a direction from which the security barrier 10 is intended to prevent vehicular penetration.
The opposing side faces 18, 20 each have at least one recess formed therein and an external fixing element 22 is located in each recess. In the example embodiment each opposing side face 18, 20 has two recesses therein and an external fixing element 22 is located in each said recess. The recesses extend along the side faces 18, 20 to a lower edge thereof.
In the security barrier 10, one or more flexible attachment 14 which extends between external fixing elements 14 of adjacent barrier islands 12 passes from the external fixing element 14, along each said recess to the lower edge thereof, and spans the separation between said adjacent barrier islands 12 substantially along a surface on which the security barrier 10 is located. As described, above by passing the flexible attachment along the ground surface, unimpeded pedestrian access between the barrier islands 12 is enabled.
In the example embodiment each recess is formed by an impact bracket 25 which comprises a steel U-channel 26 extending vertically along each opposing side face 18, 20 from a lower edge thereof. When the crash block is cast the U-channel 26 becomes embedded in the concrete crash block so that it opens onto the side face. During casting the ends and open face of the U-channel 26 may be covered, for example with a removable tape, to prevent the concrete from filling the U-channel 26. The U-bolts that form the external fixing elements 22 pass through holes that have been drilled in the U-channel 26 prior to casting, at a position above the lower edge thereof. In the example embodiment the holes for the U-bolt are vertically spaced and the lower hole is positioned 360 mm from the lower edge of the barrier island 12. The U-bolts are then attached to the U-channel by welds 23 to hold them in place, although it will be appreciated that other methods of retaining them may be used. The two threaded ends of each U-bolt extend through the U-channel 26 and project from the rear surface thereof. A clamp plate 29 is passed over the projecting threaded ends and nuts 28 are applied to retain it in place. Prior to applying the clamp plate 29 an attachment 31 of the load transfer element 24 is placed between the clamp plate 29 and the U-channel 26 such that when the nuts 28 are tightened the load transfer element 24 and the U-bolts are attached together. In this manner any tension applied to one U-bolt, for example by the flexible attachment 14 pulling tight, is transferred from the flexible attachment 14, to the U-bolt, to the load transfer element 24 via the attachment 31, to the U-bolt on the opposing face and to the flexile attachment 14 attached to the opposing side face.
In the example embodiment the load transfer element 24 comprises a nylon webbing strap having a SWL of 4 tonnes. A small eye may be sewn on each end of the webbing strap through which the attachment 31, in the form of a metal ring, is located. The metal ring is passed between the U-bolt and the clamp plate as described above to attach the load transfer element 24 to each external fixing element 22. In the example embodiment a single such load transfer element extends between each of a pair of external fixing elements 22 on one side face and a corresponding external fixing 22 element on the opposing side face. Although, in the embodiment described, a single such nylon strap is used between opposing external fixing elements 22 it will be appreciated that multiple such nylon straps may be used between opposing external fixing elements 22, attached in the same manner. Alternatively, it will be appreciated that the load transfer elements 24 could be of any material having a suitable tensile strength, either rigid or flexible, for example other suitable material includes, without limitation: straps, cables or ropes made from metal such as steel, Kevlar, or other aramid or polymer fibres; solid metal rod or strips; and composite rods or strips.
As shown in
The ends of the tubes are blanked of by plates welded thereto. The tubes 32, 34 may be stainless steel to prevent or minimise any corrosion thereof. A stainless-steel pin 36 is located in the long section 32 and is slidable therein such that in an extended position it spans the U-channel 26 such that it projects into the short section 34, and in a retracted position is substantially contained in the long section 32 such that it projects only a short distance therefrom. One or more grooves 38 may be cut into the pin 36 to create a weakened shear line intended to fracture under severe loading.
As shown in
A cover plate (not shown) may extend over the recesses to cover the flexible attachments 14 and external fixing elements 22.
The internal structure of the barrier island 12 also includes a rebar cage 40 embedded within the concrete crash block 17 below the surface thereof. The rebar cage reinforces the concrete crash block and helps to prevent fracture of the concrete under impact.
As described above, and as shown in
The two lengths of box section 42 are dimensioned so that they are the same length as the width of the formed barrier island 12. Optionally, a second two lengths of box section 44, which may be substantially identical to the first two lengths of box section 42, may be located below the rebar cage. These second two lengths of box section 44, may form additional lifting points and/or additional fixing points for seats, benches or other furniture. The length of the first two lengths of box section 42 are such that they open onto opposing faces of the formed barrier island 12. A cover may be placed over the end of each length of box section 42 to prevent concrete entering therein during the casting of the concrete around the internal structure 16. The cover may be a bespoke cover or may for example simply be a temporary cover made of tape. After the concrete is cast the covers are removed and either disposed of or used in the fabrication of further security barriers. The second two lengths of box section 44 may be arranged in a similar manner.
Referring now to
With reference to
The barrier island 12 has additional internal structure as shown in
The additional internal structure of the barrier island 12 comprises a first and second layer of pieces of metallic ballast which are in the form of steel blocks 46 located between a top face 48 and a bottom face 50 (see
The steel blocks 46 are substantially surrounded by the rebar cage 40 that extends below, above and around the array of steel blocks 46 and substantially adjacent to, but beneath, the respective exterior surfaces of the cast concrete that surrounds the internal structure 16. Although shown as a rectangular array, the steel blocks 46 may alternatively be arranged in a linear array, or irregularly. It will also be appreciated that although shown as rectangular blocks, alternative shaped pieces of metallic ballast can be used as described in more detail below. The steel blocks 46 are arranged in spaced relationship to one another such that, when encased in the cast concrete, the concrete passes around and between them in a continuous structure.
The additional mass achieved by using the metal ballast increases the resistance of the barrier islands to movement under impact.
In the example embodiment a rebar cage 40 as shown in
In an alternative arrangement the plurality of feet 62 may, after the barrier island 12 is formed, extend outwardly from the lower surface of the barrier island. This may be achieved by, during manufacture, placing a sheet beneath the rebar cage 40 through which the feet 62 extend so that after cast concrete is poured to form the barrier island 12 there is a space into which the concrete does not flow such that once the concrete is set the feet 62 extend therefrom. The feet may project in the region of 1 to 10 mm, optionally in the region of 3 to 5 mm. In use, when placed on a hard surface, for example concrete or tarmacadam, due to the weight of the barrier island 12, the feed will, under impact, act as “teeth” and provide very high pressure contact points which, if the barrier island 12 moves as a result of an impact, will dig into the surface on which it is situated, further impeding the movement thereof. On some very hard surfaces, for example granite, it may improve the performance if the feet 62 are tapered towards their outer ends to reduce the surface area of contact between the feet and the surface on which it is resting, thereby increasing the pressure at each foot.
Rubber or plastic caps (not shown) can optionally be fitted over the projecting metal feet 62. In use this allows the barrier islands 12 to be positioned and repositioned, by lifting and moving, on surfaces without the feet 62 causing damage. If, however, in use a barrier island 12 is struck, e.g. by a vehicle, with sufficient force to move it the pressure on the feet 62 will result in the caps being broken or torn off allowing the metal feet 62 to dig into the surface and further impede movement of the barrier island 12.
The steel blocks 46 and the lengths of box section 42 can then be located in the first part 52 of the rebar cage 40. The remaining two faces being a top face 64 (
Referring now to
In alternative arrangements the metallic ballast may be an alternative metal to steel, for example it may be any metal having a similar or greater density. The metallic ballast may be provided in an alternative form to steel bars. In one embodiment the metallic ballast may comprise small pieces of scrap metal (e.g. steel), for example small metal discs (or similar shape) that are produced as scrap from the punching of holes in sheet metal. The small pieces may be set in a binder to hold them together, for example cement or a resin binder. Alternatively, they may be placed in containers, e.g. sheet metal troughs. In another alternative arrangement the ballast may comprise irregular shaped pieces of metal. In another embodiment the ballast may comprise small pieces of metal, for example metal shot, metal discs, or the like, mixed with the concrete prior to casting the security barrier.
It will be appreciated that the use of additional ballast as described hereinabove is an optional feature of one embodiment and the barrier islands of the invention and may be omitted in other embodiments of the invention.
Referring to
Referring now to
Referring to
Referring to
In addition to the fence posts, spring steel security posts 82 are provided in the embedded security post footings 74 and a plurality of wires 84 as described in WO 2015/033100 are attached between the security posts 82 of adjacent barrier islands, thereby further inhibiting vehicular passage, while allowing for a greater spacing between the security barriers
Referring to
The security barrier 10 of the example embodiment was designed and manufactured to meet the requirements of the BSI IWA14.2013 collision test. In the test the security barrier 10 is placed on top of the test surface (flat concrete) without any attachment thereto or any foundations and a 7.5 tonne truck is then collided with the security barrier 10 travelling at 64 kph (40 mph).
It will be appreciated that the embodiment described herein is given as an example of the invention and that various changes and modifications can be made to the present invention without departing from the scope of the present application.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1714029.4 | Sep 2017 | GB | national |
| 1720795.2 | Dec 2017 | GB | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2018/073411 | 8/30/2018 | WO | 00 |
