Classifications

• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01F—ADDITIONAL WORK, SUCH AS EQUIPPING ROADS OR THE CONSTRUCTION OF PLATFORMS, HELICOPTER LANDING STAGES, SIGNS, SNOW FENCES, OR THE LIKE
  • E01F15/00—Safety arrangements for slowing, redirecting or stopping errant vehicles, e.g. guard posts or bollards; Arrangements for reducing damage to roadside structures due to vehicular impact
  • E01F15/02—Continuous barriers extending along roads or between traffic lanes
  • E01F15/06—Continuous barriers extending along roads or between traffic lanes essentially made of cables, nettings or the like
• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01F—ADDITIONAL WORK, SUCH AS EQUIPPING ROADS OR THE CONSTRUCTION OF PLATFORMS, HELICOPTER LANDING STAGES, SIGNS, SNOW FENCES, OR THE LIKE
  • E01F15/00—Safety arrangements for slowing, redirecting or stopping errant vehicles, e.g. guard posts or bollards; Arrangements for reducing damage to roadside structures due to vehicular impact
  • E01F15/02—Continuous barriers extending along roads or between traffic lanes
  • E01F15/04—Continuous barriers extending along roads or between traffic lanes essentially made of longitudinal beams or rigid strips supported above ground at spaced points
  • E01F15/0461—Supports, e.g. posts

Definitions

• This invention is a stanchion (post) designed to hold the ropes of a steel-rope barrier in the position intended, while simultaneously acting as an energy absorber, for example when impacted by a vehicle.
• the rope barrier is chiefly used as a safety feature in the centre or along the sides of roads and streets in order to prevent, or at least diminish, a vehicle's deviation from its own lane, thereby reducing the risk of personal injury, caused by the vehicle slewing off the roadway, or of a collision between meeting vehicles or other mobile or fixed objects, for example.
• a rope barrier consists of tensioned steel ropes, which are suspended on stanchions located at regular intervals along the stretch of road in question. In order to obtain and maintain the tension in the ropes, they are normally fitted with a tensioning device and the ends of the ropes are anchored in the ground in some way.
• a rope barrier should meet certain criteria in order for the highway authorities to approve it for installation.
• the criteria applicable to such a rope barrier could, for example, apply to the risks of personal injury and the maximum lateral stretch when impacted at specific speeds, track angle, etc., for specified vehicle types.
• the rope barrier's stanchions should hold the ropes as long as possible at the intended height and lateral positions, until the instant the vehicle collides with the stanchion.
• the vertical resistance should make it impossible for the vehicle to "crawl under” or "climb over” the barrier.
• Established standards for the maximum permissible lateral stretch of the ropes mean that the function of the stanchions as stays for the ropes is vital. If the stays give way laterally, the ability of the ropes to mobilise resistance is reduced and the lateral stretch increases substantially.
• the stanchion should bend in an incision at ground level, in order for it to collapse as fast as possible to a position parallel with the ground surface. This is so that the stanchion will not be a harmful obstruction to the vehicle. For example, an erect stanchion could damage the vehicle's chassis, fuel tank, etc., resulting in serious consequences. In addition, the stanchion, or important parts of it, must not break off because of the risk such an object poses to the surroundings.
• the ropes are secured symmetrically against the sides of the stanchion with the help of surface-mounted supports in the form of bolts, or welded-on hooks or brackets. If necessary, one or two ropes can be installed on the top of the stanchion.
• I-beam stanchion on which the ropes are located in a notch in the centre of the beam's body. The notch extends from the top of the stanchion downwards. The lower rope lies at the bottom of the notch and the other ropes are placed at regular intervals upwards in the notch, separated by plastic spacers.
• An I-beam's bending resistance is greatest against loads that act at right angles to its flanges, and lowest against loads that act at right angles to its body. This means that an I-beam could react uncontrollably and perform differently, depending on the angle at which a vehicle collides with it. With an increased angle of impact in relation to the direction in which the ropes run, the risk increases of the stanchion not bending low enough in order to prevent the I-beam's protruding and angular parts from causing serious damage to the vehicle's chassis. Furthermore, in these cases the stanchion could present such great bending resistance that the resultant braking effect is so powerful that this in itself can cause personal injury. A similar line of argument can also be applied to the other stanchions with asymmetrical bending resistance, for example the U-beam type.
• the bending resistance of a round, uniformly thick tubular stanchion does not depend on the vehicle's angle of impact, however.
• tube dimensions for example with regard to tube diameter and material thickness, it is easier than for other stanchion contours to control the stanchion's bend and its braking effect on impacting vehicles.
• the tube in itself does not have any protruding or angular parts such as U- and I-beams have.
• the stanchion holds the barrier's steel ropes in the intended vertical and lateral positions up until the instant the vehicle impacts it. This should apply irrespective of the angle at which the vehicle collides with the barrier.
• the stanchion As quickly as possible and predictably, without breaking off or loosening, plus under "reasonable" vehicle-braking energy abso ⁇ tion, bends sufficiently along an incision in it at ground level, so that the risk of injury to the vehicle occupants and persons in the vicinity because of the stanchion's reaction and design is completely avoided or is lessened to the greatest possible extent.
• the stanchion itself is shaped without protruding components such as flanges, etc. that could snag , for example, in a vehicle or unprotected driver/passengers, thereby causing further damage and/or injury.
• the stanchion is without protruding parts, such as bolts, hooks and brackets that could snag , for example, in a vehicle or unprotected driver/passengers, thereby causing further damage and/or injury.
• the main part of the stanchion is comprised of a uniformly thick tube (1), which is fitted into a matching hole in a fixed base in the ground (2).
• the base could consist of different material, vary in shape and itself have the purpose, or in co-ordination with the surrounding ground material (3), without moving to any great extent itself, of mobilising adequate and stable resistance when a vehicle collides with the stanchion (1), so that the stanchion bends close to the upper side of the base.
• the stanchion's vertical height above ground level (4) depends on the desired placement level of the ropes (5). From the stanchion's (1) top downwards, through the stanchion's (1) vertical centre line, there is a notch (6) in which the barrier's ropes (5) run at different levels parallel to the ground.
• the notch (6) is made by placing two slits (7) in the wall of the tube in a straight line with each other, i.e. 180° apart, on either side of the stanchion's (1) centre line.
• the width and length of the slits (7) depends on the diameter of the ropes (5) and the vertical placement of the ropes (5) respectively.
• the stanchion's (1) bending resistance is weakened considerably in the position of the notch (6). This means that in all probability the stanchion's (1) remaining material at the lower edge of the slits (7), i.e. at the bottom of the notch (6), will not hold up to the bending moment caused by the lateral energy of the ropes, which occurs when a vehicle collides with the rope barrier.
• This, in principle, "half-moon-shaped" part of the tube (8), which actively supports and braces against the ropes' (5) lateral tendency, will give way and release them. Thereby, the stanchion (1) loses its function as a stay for the ropes (5), upon which their ability to withstand and stop the vehicle's sideways movement is impaired. The result will thus be inferior barrier performance.
• stanchion tube (1) it is possible to fully or partially eliminate this slit drawback by modifying the dimensions of the stanchion tube (1), for example by increasing the thickness of the material. In this case, however, there is a great risk that the stanchion's (1) bending resistance will become too great, producing undesired effects on vehicle-braking and from the upright barrier stanchion (1). Consequently, the stanchion's (1) dimensions, such as tube diameter and material thickness, are chiefly governed by requirements for the stanchion's (1) cross-section and function at ground level (4).
• the ropes (5) are placed at levels as close to the bottom of the notch (6) as possible in order to reduce the bending moment, which arises from the lateral energy of the ropes that occurs when the vehicle collides with the rope barrier.
• the bending moment is at its greatest at the base of the notch (6).
• One or several rings (9) of any shape are placed around the outside, tightly fitting the remaining parts of the tube (8) and the two slits (7) in order to transfer parts of the laterally directed energy resulting from collision with the barrier from the actively resistant part of the tube (8) to the passive part (8). Because of this, in principle the cross section surface is doubled, thus contributing with bending resistance.
• the rings (9) can be placed under, between or above the ropes (5) and can consequently even have the task of acting as spacers between them (5).
• One requirement for the rings (9) is that they must have a combined tensile strength so that their (9) unified and energy- transmitting effect is not lost before the bending moment in the stanchion (1) at ground level (4) forces it (1) to bend.
• the rings (9), however, must be prevented to the greatest possible extent from leaving the stanchion (1) before the vehicle impacts it (1).
• the rings (9) could be made from various materials and be different in shape, thickness, width, etc.
• the devices (11) can be placed under, between or above the ropes (5) and can consequently even have the task of acting as spacers between them (5).
• the devices (11) One requirement for the devices (11) is that they must have combined tensile strength so that their (11) unifying and energy-transmitting effect is not lost before the bending moment in the stanchion (1) at ground level (4) forces it (1) to bend. Another requirement is that the devices (11), without themselves causing personal injury, leave the stanchion (1) or give way so that the ropes (5) are given "safe passage" out of the notch (6) when the stanchion (1) bends on being directly impacted by the vehicle. The devices (11), however, must be prevented to the greatest possible extent from leaving the stanchion (1) or from giving way before the vehicle impacts the stanchion (1), thereby counteracting any upwardly directed energy in the ropes (5) that the vehicle could generate in them (5) on impacting the barrier. In general, the devices (11) could be made from various materials, have different shapes, thickness, widths, etc.

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• Engineering & Computer Science (AREA)
• Architecture (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Aviation & Aerospace Engineering (AREA)
• Refuge Islands, Traffic Blockers, Or Guard Fence (AREA)
• Emergency Lowering Means (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20282621

Family Applications (1)

Country Status (3)

Cited By (4)

Citations (2)

• 2001
  • 2001-01-12 SE SE0100103A patent/SE516599C2/sv not_active IP Right Cessation
• 2002
  • 2002-01-10 EP EP02740063A patent/EP1419299A1/en not_active Withdrawn
  • 2002-01-10 WO PCT/SE2002/000028 patent/WO2002063103A1/en not_active Application Discontinuation

Patent Citations (2)

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