EP2313560B1 - Guardrail safety system for dissipating energy to decelerate the impacting vehicle - Google Patents
Guardrail safety system for dissipating energy to decelerate the impacting vehicle Download PDFInfo
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- EP2313560B1 EP2313560B1 EP09743469.0A EP09743469A EP2313560B1 EP 2313560 B1 EP2313560 B1 EP 2313560B1 EP 09743469 A EP09743469 A EP 09743469A EP 2313560 B1 EP2313560 B1 EP 2313560B1
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- guardrail
- terminal
- flattening
- impact
- plate
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Classifications
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- 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
- E01F15/14—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 specially adapted for local protection, e.g. for bridge piers, for traffic islands
- E01F15/143—Protecting devices located at the ends of barriers
Definitions
- the present invention relates generally to safety treatment for the ends of W-beam guardrails; and more particularly, to a tensioned guardrail terminal for dissipating impact energy of a car colliding with the end of the W-beam guardrail in an end-on or re-directive impact.
- guardrails are provided.
- the guardrails are installed such that the beam elements are in tension to aid in re-directive type impacts.
- Guardrails must be installed, however, such that the terminal end of the guardrail facing the flow of traffic is not a hazard.
- Early guardrails had no proper termination at the ends, and it was not uncommon for impacting vehicles to become impaled on the guardrail causing intense deceleration of the vehicle and severe injury to the occupants. In some reported cases, the guardrail penetrated directly, into the occupant compartment of the vehicle fatally injuring the occupants.
- guardrail designs were developed that used box beams and W-beams that allow tapering of the end of the guardrail into the ground. Such designs eliminate any spearing effect. While these end treatments successfully removed the danger of the vehicle being penetrated in a head-on collision, it was discovered that these end treatments operate in a ramp-like fashion and may induce launching of the vehicle causing it to become airborne for a considerable distance with the possibility of roll over.
- an extruder terminal was developed and typically includes a bending structure that squeezes the guardrail into a flat plate and then bends it about a circular arc directed away from the impacting vehicle.
- Example extruder terminal products include the ET 2000TM and the ET-PLUSTM offered by Trinity Highway Products.
- Other extruder terminal products include the SKT 350TM and FLEAT 350TM offered by Road Systems, Inc.
- An end treatment of a guardrail safety system according to the preamble of claim 1 is known from WO 00/32878 A .
- All of these energy absorbing systems use a cable to connect the first W-beam guardrail segment to the first post in the system.
- the cable provides tension in the guardrail beam element for a redirective hit along the length-of-need portion of the guardrail.
- a number of cable releasing posts have also been developed for use in these terminals.
- the cable release posts are intended to release the cable anchor and, thus, release the tension in the system when the post is impacted in either of a forward (end-on) or reverse direction. Such systems are not able to remain in tension during end-on and reverse-direction type impacts.
- the present invention provides a new and improved end treatment for highway guardrails.
- an end treatment of a guardrail safety system according to Claim 1.
- Technical advantages of particular embodiments of the present invention include a guardrail end treatment that dissipates impact energy through the compression of a W-beam guardrail element.
- the guardrail end treatment is energy absorbing.
- the end treatment forces the W-beam guardrail element through a flattening structure that squeezes the guardrail into a relatively flat plate.
- the guardrail end treatment dissipates impact energy of a vehicle colliding with an end of a guardrail by flattening a portion of the guardrail.
- An end of the W-beam guardrail element extends through the flattening structure and tapers to the ground.
- the W-beam guardrail element is secured to the ground in tension.
- the components of the system that provide the tensile connection of the guardrail beam to the terminal support post enables the guardrail beam to remain secured after an end-on or re-directive impact.
- the system remains in tension during both types of impacts.
- An advantage may be that the tension is released when the system is impacted in the reverse direction near the terminal end, however. The releasing of tension in the guardrail element for reverse direction impacts prevents vehicle instability and excessive deceleration.
- guardrail end treatments have proven to be unsafe for some collision conditions that happen on the highway, sensitive to installation details, and/or very costly.
- the end treatment described below is a safety treatment for the ends of a W-beam guardrail that provides a higher level of performance over a wider range of collision conditions and reduces end treatment costs and the number of injuries and deaths associated with guardrail terminal accidents.
- the described system maintains the tension in the guardrail beam element during both end-on and re-directive type impacts. When the system is impacted in the reverse direction near the terminal end, however, the anchorage system may release to prevent vehicle instability or excessive deceleration.
- FIGURE 1 illustrates a guardrail safety system 100 that incorporates certain aspects of the present invention.
- Guardrail system 100 may be installed adjacent a roadway, to protect vehicles, drivers and passengers from various obstacles and hazards, and prevent vehicles from leaving the roadway during a traffic accident or other hazardous condition.
- Guardrail systems that incorporate aspects of the present invention may be used in median strips or shoulders of highways, roadways, or any path that is likely to encounter vehicular traffic.
- Guardrail system 100 includes a guardrail beam 102 and support posts 104 that anchor guardrail beam 102 in place along the roadway.
- guardrail beam 102 may include multiple 12-gauge W-beam rail elements of a length on the order of approximately 3.8 m (12.5 feet) or 7.6 m (25 feet).
- the guardrail beam sections may be mounted at a height of on the order of approximately 0.69-0.79 m (27 to 31 inches) with rail splices positioned mid- span between the support posts 104.
- Guardrail beam 102 and the terminal end of guardrail beam 102 are illustrated in more detail in FIGURES 4A and 4B and will be described below.
- Guardrail beam 102 is attached to support posts 104 with connectors that may include, in particular embodiments, slotted countersunk bolts such as, for example, 16 mm (5/8-inch) diameter by 38 mm (1-1/2-inch) long flat slot machine screws. Oversized guardrail nuts may be used on the back side of the support post 104.
- Support posts 104 may be embedded in the ground, a concrete footing, or a metal socket. Support posts 104 may be made of wood, metal, plastic, composite materials, or any combination of these or other suitable materials. It is also recognized that each support post 104 within guardrail system 100 need not necessarily be made of the same material or include the same structural features. Furthermore, the cross-section of support posts 104 may be any engineered shape suitable for releasably supporting guardrail beam 102. Such cross-sectional shapes may include, but are not limited to, square, rectangular, round, elliptical, trapezoidal, solid, hollow, closed, or open.
- Guardrail system 100 is intended to keep errant vehicles from leaving the roadway during a crash or other hazardous situation.
- guardrail 100 is installed between a roadway and a significant hazard to vehicles (e.g., another roadway, a bridge, cliff, etc.). Therefore, guardrail system 100 should be designed to withstand a significant impact from a direction generally perpendicular to the roadway, without substantial failure. It is this strength that allows guardrail system 100 to withstand the impact, and still redirect the vehicle so that it is once again traveling generally in the direction of the roadway.
- guardrail systems may actually introduce additional hazards to the roadway and surrounding areas. This is particularly true with respect to vehicles that impact the guardrail system adjacent its terminal section, in a direction generally parallel to the roadway. For example, if the guardrail system were rigidly fixed in place during a crash, serious injury and damage may result to the errant vehicle, its driver and passengers. Accordingly, many attempts have been made to minimize this added risk. Such methods generally include the use of terminal portions that are tapered from the ground up to effectively reduce the impact of head on collisions and to create a ramp- like effect that causes vehicles to go airborne during a crash.
- breakaway cable terminals BCT
- vehicle attenuating terminals VAT
- SENTRE end treatments BET
- breakaway end terminals BET
- breakaway support posts U.S. Patent No. 6,398,192
- Many-such terminals, supports, end treatments and the like are commercially available from various organizations. Examples include the HBA post by Exodyne Technologies and Trinity Industries, and a breakaway support post similar in configuration to that described in the 192 Patent.
- guardrail system 100 includes one terminal post 106 and seven support posts 104. Collectively, this configuration forms a terminal section 108 of guardrail system 100. As shown, terminal section 108 is employed in a preferred embodiment as an end terminal for a conventional guardrail assembly 100.
- FIGURE 1 is illustrated with dimensions and depicts one exemplary embodiment, it is understood that the dimensions of guardrail system 100 may vary depending on the nature of the roadside hazard being shielded. As illustrated, each terminal section 108 has a length on the order of approximately 10.7 m (35 feet). However, the dimensions of terminal section 108 may vary as needed. Additionally, the length of the length-of-need portion of the system may of any appropriate length required by the conditions of the roadway.
- Terminal section 108 may be installed either parallel to the roadway or at an angular departure from the roadway, as shown best in FIGURE 1 . Additionally, while the terminal section 108 at one end of the guardrail safety system may be flared, the terminal section 108 at the opposite end of the system may not be flared, in certain embodiments. For example, in the embodiment depicted in FIGURE 1 , an upstream terminal section 108 is flared while a downstream terminal section 108 is not flared. Specifically, the upstream terminal sections 108 is flared away from the roadway in a substantially linear manner while the downstream terminal section 108 remains substantially parallel to the roadway. In other embodiments, both terminal sections 108 may be flared or unflared in a similar manner.
- terminal sections 108 may be installed at a parabolic flare away from the roadway.
- a parabolic flare may be accomplished by increasing the offset of each support post in a generally parabolic progression as the terminal portion proceeds upstream.
- terminal section 108 positioning of one or more of terminal sections 108 at a flared or angular departure away from the roadway may permit the terminal sections 108 to perform a gating function by facilitating movement of the impacting vehicle to the side of the rail opposite the roadway as the vehicle progresses.
- terminal section 108 may be flared back at an angle of approximately 6 to 7 degrees from the non-terminal portion of the guardrail.
- support posts 104 of terminal section 108 are spaced apart at intervals of approximately 1.9 m (75 inches)
- the most downstream post 104 of terminal section 108 may be approximately 0.23 m (9 inches) offset from a line tangent to the non-terminal portion of the guardrail, in a particular embodiment.
- the next four successive support posts 104 may be 0.48, 0.74, 0.99 and 1.22 m (19, 29.25, 39, and 48 inches) offset from a line tangent to the non-terminal portion of the guardrail, in this embodiment.
- Terminal post 106 which may be positioned directly below guardrail beam 102, may be approximately 1.19 m (47 inches) offset from a line tangent to the non-terminal portion of the guardrail, in the described embodiment.
- terminal section 108 includes an end treatment 110.
- End treatment 110 includes a flattening chute 112 and a front striking plate 114.
- End treatment 110 and flattening chute 112 specifically, is mounted onto a first post 104 by fasteners such as bolts.
- the purpose of end treatment 110 is to dissipate impact energy of the vehicle without creating a dangerous condition such as causing the vehicle to roll-over or allow the guardrail 102 to spear the vehicle or the occupant compartment of the vehicle.
- Guardrail beam element 102 feeds into an inlet 116 at a downstream end of flattening chute 112.
- Guardrail beam element 102 is disposed within flattening chute 112 and extends the length of flattening chute 112.
- Guardrail beam element 102 exits an outlet 118 at an upstream end of flattening chute 112.
- the dimensions of flattening chute 112 results in a terminal portion of the guardrail beam 102 tapering to the ground.
- the portion of guardrail beam element 102 exiting outlet 118 is flattened vertically such that the terminal portion of guardrail beam element 102 resembles a stack of four flat plates.
- a terminal post 106 secures the terminal end of guardrail beam element 102 to the ground and places guardrail beam element 102 in tension.
- the coupling of guardrail beam element 102 to terminal post 106 enables guardrail beam element 102 to remain secured in tension to terminal post 106 after either of an end-on or redirective impact by a vehicle leaving the roadway.
- the components effecting the tensile coupling enables the tension in guardrail beam element 102 to be released when the system is impacted in the reverse direction near the terminal end.
- FIGURE 3 illustrates an exemplary embodiment of end treatment 110 in greater detail.
- end treatment 110 includes a flattening chute 112 and a front striking plate 114.
- Flattening chute 112 and front striking plate 114 are coupled to an extruder 120.
- Extruder 120 surrounds the upstream portion of guardrail beam member 102 and is made up of an upper, U-shaped channel member 122 and a lower, U-shaped channel member 124, which are secured in a spaced relation to one another by strap plates 126.
- the vertical distance between channel members 122 and 124 is an appropriate distance such that guardrail beam 102 is inserted into the channel created by extruder 120.
- guardrail beam 102 comprises a 12-gauge W-beam rail element having a vertical dimension of approximately 0.31 m (12.25 inches)
- the distance between the top of channel member 122 and the bottom of channel 124 may be approximately 0.36 m (14 inches), in a particular embodiment.
- Front striking plate 114 is secured by welding to extruder 120 of end treatment 110.
- Front striking plate 114 may be vertically elongated, in particular embodiments. Thus, front striking plate 114 may extend both above and below extruder 120 to permit front striking plate 114 to be easily engaged by either the high bumper of trucks, SUV's, and other taller vehicles and the low set bumpers of smaller cars impacting in a frontal manner.
- Front striking plate 114 is also positioned so as to engage the vehicle frame or rocker panel to reduce vehicle intrusion when the upstream end of end treatment 110 is impacted by a vehicle in a sideways manner.
- Flattening portion 112 which is mounted to extruder 120, may be constructed from four metal plates, in a particular embodiment. The four metal plates may be cut and/or bent and then welded together to form the desired configuration. Alternatively, flattening portion 112 may be formed from more than four pieces or from a single piece of metal that is cut and bent into the desired configuration. When flattening portion 112 is assembled, flattening portion 112 may form an enclosed structure that houses a terminal portion of guardrail beam 102.
- flattening portion 112 includes three sections.
- the most downstream portion of flattening portion 112 includes a throat 128.
- the vertical dimension of throat 128 is greater at the downstream end and decreases as it approaches the upstream end of end treatment 110.
- the vertical dimension of throat 128 may be approximately 0.36 m (14 inches) wide at the downstream end and approximately 0.11 m (4.5 inches) wide at the upstream end.
- the horizontal length of throat 128 may be within a range of approximately 0.28 to 0.33 m (11 to 13 inches).
- the slope of a lower edge 132 may be greater than the slope of an upper edge 130.
- the increased slope of lower edge 132 may aid in the flattening of guardrail beam 102 during an impact.
- upper edge 130 may slope upward at an angle of approximately 11 degrees from the horizontal
- lower edge 132 may slope downward at an angle of approximately 13 degrees from the horizontal.
- the slope of upper edge 130 and lower edge 132 may be substantially the same.
- upper edge 130 and lower edge 132 may symmetrically mirror one another.
- one of top edge 130 and lower edge 132 may be aligned with the horizontal (substantially parallel with the roadway) while the other of top edge 130 and lower edge 132 slopes upward or downward, respectively.
- a mid portion 134 extends from the upstream end of throat 128 and slopes toward the ground. Specifically, mid portion 134 is configured to transition guardrail beam element 102 from a height above the ground level that is appropriate for redirecting an impacting vehicle (0.79 m (31 inches), in a particular embodiment) to a height that is proximate the ground's surface. Thus, mid portion 134 extends from a vertical distance associated with throat 128 at a downstream end to approximately ground level at an upstream end. In a particular embodiment, where the horizontal length of mid portion 134 is approximately 0.48 m (18.75 inches), mid portion 134 may slope at an angle of approximately 38 degrees from the horizontal.
- Mid portion 134 also provides a channel through which a terminal portion of guardrail beam element 102 is disposed.
- the vertical dimension of the channel within mid portion 134 may be approximately 0.11 m (4.5 inches) (similar to the width of throat 128 at the upstream end).
- the dimensions of the channel within mid portion 134 may remain substantially constant such that the vertical dimension of the channel within mid portion 134 at the downstream end is the substantially the same as the vertical dimension of the channel within mid portion 134 at the upstream end.
- a third portion of flattening portion 112 includes outlet portion 136.
- Outlet portion 136 extends from the upstream end of mid portion 134.
- Outlet portion 136 is disposed proximate the grounds' surface and is in substantial alignment with the grounds' surface.
- Outlet portion 136 also forms a channel through which the terminal end of guardrail beam element 102 exits the flattening chute 112.
- the vertical dimension of the channel within outlet portion 136 may be approximately 0.11 m (4.5 inches) (similar to the vertical dimension of the channel within mid portion 134).
- the dimensions of the channel within outlet portion 136 may remain substantially constant such that the vertical dimension of the channel at the downstream end of outlet portion 136 is substantially the same as the vertical dimension of the channel at the upstream end of outlet portion 136.
- the horizontal length of outlet portion 136 may be approximately 0.13-0.18 m (5-7 inches).
- guardrail beam member 102 is disposed within and extends throughout the length of flattening portion 112. Specifically, guardrail beam member feeds into an inlet 116 at a downstream end of flattening chute 112. Guardrail beam element 102 traverses the length of flattening chute 112 and exits an outlet 118 at an upstream end of flattening chute 112. Thus, a terminal end of the W-beam guardrail element extends through the flattening structure.
- the slope of mid portion 134 toward the ground in the upstream direction results in guardrail beam element 102 being gradually transitioned toward the ground over the length of flattening portion 112. After exiting the outlet 118, guardrail beam element 102 is secured to a terminal post 106 at ground level.
- end treatment 110 may be displaced in a downstream direction and downstream portions of guardrail beam element 102 may be forced into the displaced end treatment 110.
- extruder 120 functions as a guide to guide guardrail beam element into flattening portion 112.
- Extruder 120 includes guides 138 that prevent shaving of the W-beam guardrail element 102 by ends of extruder 120 as extruder 120 moves along the length of the guardrail beam element 102 during a collision.
- the guides 138 accommodate any irregularities or bumps in guardrail beam element 102 to ensure proper feeding of guardrail beam element 102 into flattening portion 112.
- guardrail beam element 102 is flattened vertically. Portions of guardrail beam element 102 exiting outlet 118 of flattening portion 1 12 are flattened into what may appear to be four vertically stacked plates. For example, where the vertical dimension of guardrail beam element 102 is approximately 0.31 m (12.25 inches) and throat portion 134 of flattening portion 112 is approximately 0.11 m (4.5 inches), the vertical dimension of the flattened portion of guardrail beam element 102 may be less than approximately 0.11 m (4.5 inches). As this flattening process occurs, substantial energy is dissipated slowing the impacting vehicle.
- FIGURES 4A and 4B illustrate a modified guardrail beam element 200 in accordance with one embodiment.
- the guardrail beam element 200 includes a slotted zone 202 at the upstream end of the terminal portion of guardrail beam element 200.
- slotted zone 202 comprises a series of slots longitudinally disposed in the guardrail beam element 200. The use of three slots has proven effective in testing models of guardrails constructed similar to guardrail safety system 100. Slotted zone 202 may initiate at a terminal end 203 of guardrail beam element 200 and extend a desired distance downstream.
- slotted zone 202 may vary depending on the horizontal length of end treatment 110. It may be desirable for slotted zone 202 to include the portion of guardrail beam element 200 that is coupled to terminal post 106 and the portion of guardrail beam element 200 that traverses through flattening portion 112. Generally, slotted zone 202 may extend from the terminal, upstream end of guardrail beam element 200 to some distance between the first and second support posts 104. Where, for example, the dimensions of the terminal section 108 of guardrail system 100 are similar to those illustrated in FIGURE 1 , slotted zone 202 may extend approximately 2.0-2.2 m (80-85 inches) from the terminal end of guardrail beam element 200.
- slots in slotted zone 202 may be better understood with reference to the cross-section for a typical W-beam guardrail 200 as shown in FIGURE 4B .
- a valley 204 is positioned between upper and lower peaks 206 and is formed at the intersections of inclined web portions 208. Edge members 210 laterally out lie each peak 206. Highly preferred placement for the slots is proximate each peak 206 and the valley 204.
- first and second slots 212 are placed in the first and second peaks 206, respectively.
- a third slot 214 is placed in valley 204. Slots 212 and 214 should be of a size sufficient to enhance the ability of the terminal end of guardrail beam element 200 to be flattened.
- each peak 206 and valley 204 may be removed.
- Effective sizes for slots 212 have been found to be approximately 0.013 m (0.5 inches), as measured vertically.
- An effective size for slot 214 has been found to be approximately 0.019 m (0.75 inches), as measured vertically.
- slots 212 may have a width on the order of 0.013 m (0.5 inches) and extend approximately 2.06-2.08 m (81-82 inches).
- Slot 214 may have a width on the order of approximately 0.019 m (0.75 inches) and extend approximately 2.06-2.08 m (81-82 inches).
- the provided dimensions are for example purposes only, however. Any dimensions may be used for slots 212 and 214 to enhance the ability of guardrail beam 200 to be flattened into four vertically stacked plates throughout the terminal end of guardrail beam element 200.
- guardrail system 100 may vary as desired.
- the impacting vehicle and end treatment 110 may engage one or more support posts 104.
- the support posts 104 comprises steel yielding support posts that are modified at ground level
- the impacted support posts 104 may release guardrail beam element 102 as they are impacted and bent toward the ground.
- support posts 104 that are impacted during the collision may be displaced, in certain embodiments, such that they do not pose a hazard to the impacting vehicle.
- guardrail beam 102 may be released from impacted support posts 104, portions of guardrail beam element 102 downstream from the impact may remain in substantially their original position relative to the ground's surface. Further, because guardrail beam 102 remains coupled to terminal post 106 during an end-on or re-directive impact, guardrail beam 102 remains in tension. This extends the range of acceptable performance of guardrail safety system 100.
- guardrail beam 102 may also be retained in this manner when guardrail system 100 is subject to a re-directive impact in the length of need portion of guardrail system 100.
- any support posts 104 impacted by the vehicle may operate to release guardrail beam element 102 as they are impacted.
- Modified support posts 104 may be bent toward the ground such that the support posts 104 are displaced and do not pose a hazard to the impacting vehicle. Because the tension in guardrail beam 102 is maintained, guardrail beam element 102 continues to operate to redirect the vehicle back onto the roadway even after one or more support posts are released from guardrail beam element 102.
- FIGURES 5A-5C, 6A-6C, and 7A-7C illustrate example embodiments of support posts that may be used in conjunction with guardrail system 100 of FIGURE 1 .
- FIGURES 5A-5C illustrate an exemplary weakened support post that may be used as a first support post 500 (after the terminal support post 106) in the terminal section 108 of guardrail safety system 100.
- FIGURES 6A-6C illustrate an exemplary weakened support post 600 that may be used throughout terminal section 108 and other portions of guardrail safety system 100.
- FIGURES 7A-7C illustrate a standard line post 700 that may be used in certain portions of guardrail safety system 100.
- FIGURES 5A-5C, 6A-6C, and 7A-7C illustrate three distinct embodiments, respectively, like reference numerals have been used to identify parts common to the three embodiments.
- support posts 500, 600, and 700 include elongate, continuous structural members and are each of a standard wide flange configuration.
- Each support post includes two flanges 502, that are generally parallel with one another, and in spaced apart relation from one another.
- a web 504 forms the coupling between flanges 502.
- flanges 502 include a generally identical configuration of boltholes 506 and cutouts 508, therein.
- the cross section is typically shaped like the letter "H".
- the cross section has two major axes for bending.
- the "weak” axis generally refers to a central axis that extends through the web and is perpendicular to the flanges.
- the “strong” axis generally refers to a central axis that is perpendicular to the web and parallel to the planes of the flanges.
- the weak axis for a conventional installation of guardrail extends generally transversely to the road.
- the strong axis extends generally along the roadway.
- the wide flange is a standard W6x8.5, which is commonly used in fabricating support posts for guardrail installations.
- a standard W6x8.5 wide flange may have a nominal six-inch depth and weigh eight and one-half pounds per foot.
- one advantage of the present invention is the ability to re-use existing, standard equipment to fabricate, modify, and install support post 500, without substantial modification to the equipment.
- wide flange beams may be available in many different sizes. For example, a wide flange having a six-inch depth and weighing nine pounds per foot may also be used.
- Such a wide flange is referred to as a W6x9 wide flange.
- a W6x9 wide flange and a W6x8.5 wide flange are considered equivalent in the trade.
- the terms "W6x8.5 wide flange” and “W6x9 wide flange” are intended to refer to all sizes and configurations of guardrail posts that may be referred to as “W6x9” by a person of ordinary skill in the art.
- persons skilled in the art recognize other names used for wide flanges include but are not limited to "I-beam,” “H-beam,” “W-beam,” “S-beam,” “M-beam,” or the term “shape” may be substituted for "beam.”
- Support posts 500, 600, and 700 have a length in a range of approximately 72 and 73 3/8 inches, in particular embodiments, and include an upper portion 510 and a lower portion 512.
- a mid portion 514 couples upper portion 510 with lower portion 512.
- Upper portion 510 includes two boltholes 506 that are adapted to receive connectors for the installation of a guardrail beam (e.g., guardrail beam 102) upon the support post.
- Lower portion 512 is suitable for installation below grade, as part of a guardrail support system.
- Bolt holes 506 include a standard configuration that allow for the installation of widely used guardrail beams, upon the respective support post.
- bolt holes 506 align with the center of the guardrail beam, and maintain the center of the guardrail beam approximately 0.76 m (30 inches) above grade.
- the number, size, location and configuration of boltholes 506 may be significantly modified, within the teachings of the present invention .
- Support posts 500 and 600 are each modified to include a relatively "weak” axis W, and a relatively “strong” axis S.
- Support posts 500 and 600 are normally installed along a roadway such that weak axis W is generally perpendicular to the direction of traffic, and strong axis S is generally parallel to the direction of traffic. Accordingly, support posts 500 and 600 are typically able to withstand a significant impact (e.g., with a car traveling at a high rate of speed) about the strong axis S without substantial failure.
- support posts 500 and 600 are intentionally designed such that failure will more readily occur in response to an impact about the weak axis W. Stated differently, support posts 500 and 600 exhibit adequate strength in the lateral direction but sufficiently low strength in the longitudinal direction.
- support posts 500 and 600 will tend to fail (e.g., buckle), while allowing the vehicle to decelerate as it impacts consecutive support posts.
- support posts 500 and 600 will provide sufficient resistance (strength) to redirect the vehicle along a path generally parallel with guardrail beam 102.
- Mid portions 514 of support posts 500 and 600 include two cutouts 508, which are configured to further weaken the support posts about the weak axis W, to more readily allow for failure due to impact from a vehicle along that direction. Cutouts 508 are positioned within mid portion 514 to weaken the support posts about weak axis W, adjacent grade (when installed). This will accommodate failure of the support posts approximately at grade, allowing support posts 500 and 600 to "fold" over from the point of failure, upward. Since lower portion 512 is below grade, it is not expected that the ground, or lower portion 512 of the support post will appreciably deflect during an impact.
- cutouts 508 are intended to occur approximately at grade, and the center of bolt holes 506 are intended to occur 0.76 m (30 inches) above grade, bolt holes 506 occur 30 inches above cutouts 508, in the illustrated embodiment. It will be recognized by those of ordinary skill in the art that the size, configuration, location and number of bolt holes, cutouts, and their relationship with each other, may be varied significantly within the teachings of the present invention. The overall length of the support posts, and their respective upper, lower and mid portions may vary significantly, within the teachings of the present invention. For example, in other embodiments, cutouts 508 may occur below grade or above grade. The depth of cutouts 508 below grade should not exceed an amount that will prevent the support posts from failing at or near the location of cutouts 508. At some depth below grade, the surrounding earthen (or other) material will reinforce lower portion 512 of the support posts to an extent that will no longer accommodate such failure to occur.
- the height of cutouts 508 above grade should not exceed a point at which the support post will fail at cutouts 508, and leave a "stub" above grade which can snag vehicles, and otherwise cause excessive injury and/or excessive damage. Such a stub could be detrimental to the redirective effect of the guardrail system in which the support post is operating.
- the vertical dimension of a cutout 508 is limited based upon the horizontal dimension of cutout 508. For example, a ratio of the vertical dimension of any particular cutout may be equal to, or less than three times the horizontal dimension. Alternatively, the ratio may be limited to two times the horizontal dimension. In the illustrated embodiments, the ratio is 1:1, since cutout 508 is generally a circular opening in the support post. The smaller the vertical dimension of the cutout, the more precisely the designer may dictate the point of failure along the vertical length of support posts 500 and 600.
- cutouts 508 are available to a designer of support posts 500 and 600, in accordance with the teachings of the present invention.
- cutouts 508 may comprise square, rectangular, triangular, oval, diamond shaped, or practically any other geometric configuration, and still obtain some or all of the benefits described herein.
- cutouts 508 within flanges 502 may also be altered significantly, within the teachings of the present invention.
- the centerline of cutouts 508 is located approximately one inch from the centerline of flanges 508.
- cutouts 508 may be located closer to such edges, or further from such edges.
- cutouts 508 may be configured such that they extend all the way to the edge of the flange, such that there is a break in material beginning at the edge. In this manner, a traditional punch could be employed at the edge, to form a semi-circular opening that extends to the edge of the flange.
- a sawcut could be employed from the outer edge of the flange, and extending inward, to form cutouts 508. In this manner, the sawcut would form the starting point of the likely point of failure along the weak axis of the support post.
- a similar configuration may include a slot in which the longest dimension extends horizontally through the flange. Such a slot may begin or terminate at the edge of the flange, or otherwise be disposed completely within the material of the flange.
- FIGURES 5A-5C specifically illustrate a guardrail support post 500 that may be used as the first support post (after the terminal support post 106) in a guardrail system 100.
- support post 500 may be modified to support an end treatment 110.
- support post 500 includes additional boltholes 520 and 522 for coupling end treatment 110 to support post 500.
- boltholes 520 and 522 are slightly smaller than boltholes 506 and cutouts 508. It is recognized, however, that the provided dimensions of boltholes 520 and 522 are provided for example purposes only and may vary as appropriate for coupling the end treatment 110 to support post 500.
- support posts 600 and 700 do not include additional boltholes 520 and 522 and, thus, are more appropriately used in portions of the guardrail system 100 that are not directly supporting end treatment 110.
- guardrail support post 700 does not include cutouts 508 and may comprise standard line posts such as unmodified W6x8.5 posts or any other support post of an appropriate size, weight and configuration.
- FIGURES 8A and 8B illustrate an example embodiment of a terminal support post 800 that may be used in conjunction with guardrail system 100 of FIGURE 1 .
- terminal support post 800 is the first terminal support post at the upstream end of terminal section 108.
- FIGURE 8A is a side view of terminal support post 800, and
- FIGURE 8B is a front view of the same terminal support post 800.
- terminal support post 800 is releasably coupled to guardrail beam 102 such that guardrail beam 102 and provides positive anchorage of guardrail beam 102 to react to tensile loads on guardrail beam 102 to redirect a vehicle impacting laterally along the length of guardrail beam 102.
- Various components are used to effect the coupling of guardrail beam 102 to terminal support post 800 such that guardrail beam 102 remains coupled to terminal support post 800 when guardrail system 100 is struck by an impacting vehicle in an end-on or re-directive type impact.
- guardrail beam element remains supported in tension even after such an impact.
- the tensile coupling of guardrail beam 102 will be released from terminal support post 800 to prevent vehicle instability and excessive vehicular deceleration.
- terminal support post 800 includes a structural member 802 of an I-beam configuration.
- Structural member 802 includes a pair of flanges 804 interconnected by a central web 806.
- the beam member 802 comprises a W 6x15 steel post member.
- a pair of rectangular side plates 808 are affixed opposite sides of structural member 802.
- side plates 808 are secured by welding to each of flanges 804.
- a connector assembly is used to couple structural member 802 to the guardrail beam member.
- the connector assembly is configured such that the coupling of the structural member and the terminal portion of the guardrail beam is maintained during an end-on or re-directive impact by a vehicle.
- the connector assembly is configured to release the coupling during a reverse-direction impact.
- the connector assembly comprises a plurality of stacked rectangular plates that are aligned to receive the terminal portion of the guardrail beam.
- the connector assembly may include a stack of three plates: a flange plate 810, a keeper plate 816, and a washer plate 824.
- a flange plate 810 is secured between side plates 808.
- Flange plate 810 is preferably a unitarily formed piece that is secured by welding to structural member 802 and each side plate 808.
- Flange plate 810 includes a rectangular plate with a V-shaped cut-out 812 at the center of an upper edge 813 of flange plate 810.
- flange plate 810 has a length of approximately 0.13 m (5 inches) and a width of approximately 0.15 m (6 inches).
- the thickness of flange plate 810 as best shown in FIGURE 8B , may be approximately 0.025 m (1 inch).
- V-shaped slot 812 is centered along the horizontal width of flange plate 810 and has a vertical length of approximately (0.03) 1 inch and a horizontal width of approximately 0.04 m (1 3/4 inches).
- the rounded bottom 814 of V-shaped slot 812 has a diameter of approximately 0.03 m (1 1/4 inches).
- the described and depicted dimensions of flange plate 810 are provided for example purposes only. Although the depicted dimensions may be appropriate where structural member 802 includes a W6x15 steel post member, the dimensions of flange plate 810 may vary and may depend on size and dimensions of structural member 802.
- a keeper plate 816 is disposed adjacent to flange plate 810. Similar to flange plate 810, keeper plate 816 is preferably a unitarily formed piece. As best shown in FIGURE 9B , keep plate 816 includes a rectangular plate with a circular shaped opening 818 proximate an upper edge 820 of keeper plate 816. In the illustrated embodiment, keeper plate 816 has a vertical length of approximately 0.08 m (3 1/8 inches) and a horizontal width of approximately 0.14m (5 3/8 inches). Opening 818 is centered along the horizontal width of keeper plate 816 and has a center that is approximately 0.02 m (7/8 inch) from upper edge 820 of keeper plate 816.
- U-shaped opening 818 may have a diameter of approximately 0.03 m (1 1/4 inches).
- keeper plate 816 are provided for example purposes only. Although the depicted dimensions may be appropriate where structural member 802 includes a W 6x15 steel post member, the dimensions of keeper plate 816 may vary and may depend on size and dimensions of structural member 802 and flange plate 810.
- washer plate 824 is disposed adjacent to keeper plate 816. Similar to flange plate 810 and keeper plate 816, washer plate 824 is preferably a unitarily formed piece. As best shown in FIGURE 9C , washer plate 824 includes a rectangular plate with a U-shaped slot 826 at the center of the upper edge 828 of washer plate 824. In the illustrated embodiment, washer plate 824 has a vertical length of approximately 0.1 m (4 1/8 inches) and a horizontal width of approximately 0.14 m (5 1/2 inches). The thickness of washer plate 824, as best shown in FIGURE 8B , may be approximately 0.01 m (1/2 inch).
- U-shaped slot 826 is centered along the horizontal width of washer plate 824 and has a vertical length of approximately 0.03 m (1 1/4 inches) and a horizontal width of approximately 0.028 m (1 1/8 inches).
- the rounded bottom slot 826 has a diameter of approximately 0.03 m (1 1/4 inches).
- the described and depicted dimensions of washer plate 824 are provided for example purposes only. Although the depicted dimensions may be appropriate where structural member 802 includes a W 6x15 steel post member, the dimensions of washer plate 824 may vary and may depend on size and dimensions of structural member 802.
- Each of flange plate 810, keeper plate 816, and washer plate 824 include a pair of boltholes 830.
- boltholes 830 are approximately 0.01 m (3/8 inches) in diameter.
- a pair of threaded bolts 832 may be secured through boltholes 830 to secure flange plate 810, keeper plate 816, and washer plate 824 together.
- a washer 834 may be threaded onto the end of each of the threaded bolts 832 to hold the plates relative to each other.
- FIGURES 10A and 10B illustrate an exemplary tensile connection of a guardrail beam 1000 to a terminal support post such as terminal support post 800 depicted in FIGURES 8A and 8B .
- a compressed slotted guardrail beam 1000 similar to those described above with regard to FIGURES 1, 2 , and 4A-4B is coupled to a connection plate 1002.
- connection plate 1002 includes a pair of boltholes 1004, which may be aligned with a pair of similar boltholes (not shown) in the terminal end of the compressed slotted guardrail beam 1000.
- a pair of threaded bolts 1006 may be threaded through boltholes 1004 and similarly sized boltholes of guardrail beam 1000 (not shown) that are aligned with boltholes 1004.
- a threaded nut 1008 may secure each connection of bolts 1006 through connection plate 1002 and guardrail beam 1000.
- the boltholes 1004 and boltholes in guardrail beam 1000 may have a diameter on the order of approximately 7/8 inch.
- threaded bolts 1006 may include 2 1/2 x 3/4" GR. 5 bolts. However, it is recognized that these sizes are provided as examples only. Any appropriate size of boltholes and bolts may used to secure guardrail beam 1000 to connection plate 1002.
- Connection plate 1002 is coupled to a threaded rod 1010.
- threaded rod 1010 may be welded to connection plate 1002.
- threaded rod 1010 is threaded through V-shaped cutout 814 of flange plate 810, circular opening 818 of keeper plate 816, and U-shaped cutout 826 of washer plate 824.
- a nut 836 is threaded on the end of threaded rod 101 to secure guardrail beam 1000 in tension to terminal support post 800.
- nut 836 prevents withdrawal of cable 1010 from the openings formed by V-shaped cutout 814 of flange plate 810 and U-shaped cutout 826 of washer plate 824. Since the opening of keeper plate 816 includes an enclosed circular opening 818 rather than an open cutout in the edge of the keeper plate 816, keeper plate 816 ensures that threaded rod 1010 is properly in place. Keeper plate 816 also adds strength to the tensile connection of threaded rod 1010 to terminal post 800. Washer plate 824, which functions as a washer between bolt 834 and keeper plate 816, also adds strength to the connection.
- guardrail beam 1010 During an end-on or redirective impact to a guardrail system incorporating the above-described features, the assembly described in FIGURES 8A-8B , 9A-9C , and 10A-10B enables the tensile connection of guardrail beam 1010 to terminal support post 800 to remain intact. Because the guardrail beam 1010 remains in tension, guardrail beam 1010 is able to redirect the impacting vehicle. Column buckling of the system may be eliminated and an eccentric impacting vehicle may remain in the system longer during deceleration.
- guardrail beam 1000 may be controllably collapsed to prevent vehicle instability or excessive deceleration.
- a modified strut may be used to couple the terminal support post to the first adjacent support post.
- strut 140 includes a longitudinal beam member 1112 that has been modified to include a strut plate 1114.
- Longitudinal beam member 1112 may include have any appropriate cross-sectional shape.
- the length of longitudinal beam member 1112 is appropriate for coupling terminal support post 106 and the next adjacent support post 104.
- longitudinal beam member 1112 may include a C-channel member having a width on the order of approximately 0.15 m (6 inches) and a depth on the order of approximately 0.05 m (2 inches).
- strut plate 1114 is preferably a unitarily formed piece that is secured by welding to longitudinal beam member 1112.
- Strut plate 1114 includes a rectangular plate with a U-shaped cut-out 1116 at the center of the upper edge 1118 of strut plate 1114.
- strut plate 1114 has a horizontal dimension of approximately 0.25 m (10 inches) and a vertical dimension of approximately 0.02 m (8 inches). The thickness of strut plate 1114 may be approximately 0.01 m (1/4 inch).
- U-shaped slot 1116 is centered along the vertical dimension of strut plate 1114 and has a vertical dimension of approximately 0.04 m (1 1/2 inch) and a horizontal dimension of approximately 0.14 m (5 1/2 inches).
- the rounded bottom 1120 of U-shaped slot 1116 has a diameter of approximately 0.04 m (1 1/2 inches).
- strut plate 1114 is provided for example purposes only.
- the dimensions of strut plate 1114 and longitudinal beam member 1112 may vary.
- strut 1112 and strut plate 1114 may facilitate the release of the tensile connection between the guardrail beam and the terminal support post.
- Strut plate 1114 is positioned proximate the outlet end of flattening portion 112.
- Strut plate 1114 operates as a ramp to facilitate the lifting of the threaded rod coupled to the guardrail beam from the V- shaped cutout 814 of flange plate 810, circular opening 818 of keeper plate 816, and U-shaped cutout 826 of washer plate 824. Because the tensile connection in guardrail beam 1000 is released, strut 1112 and strut plate 1114 prevent instability or excessive deceleration of the impacting vehicle.
- FIGURES 10A and 10B illustrate an exemplary tensile connection of a guardrail beam to a threaded rod.
- FIGURE 12 illustrates an example of a tensile connection that may be used to couple a guardrail beam to a terminal post and which does not form part of the present invention.
- a slotted guardrail beam 1200 may be modified similar to guardrail beam 200 of FIGURE 4A .
- Slotted guardrail beam 1200 is modified at the terminal end 1202 and is coupled to a cable rod 1204.
- slotted guardrail beam 1200 may be coupled to a pair of cable rods 1204.
- Cable rods 1204 may traverse through a flattening portion 1206.
- Flattening portion 1206 may be similar to flattening portion 110 of FIGURES 1-3 . Accordingly, at least a portion of cable rods 1204 may traverse the length of flattening portion 1206 and exit an outlet 1206 at an upstream end of flattening portion 1206. After exiting the outlet 1206, cable rods 1204 may be secured to a terminal post 106 at ground level using a mechanism similar to that described above with regard to FIGURES 8A-8B , 9A-9C , and 10A-10B .
- Technical advantages of particular embodiments of the present invention include a guardrail end treatment that dissipates impact energy through the compression of a W-beam guardrail element.
- the guardrail end treatment may dissipate impact energy of a vehicle colliding with an end of a guardrail by flattening a portion of the guardrail required for deceleration of the impacting vehicle.
- Another advantage may be that the end treatment forces the W-beam guardrail element through a flattening structure that squeezes the guardrail into a relatively flat plate.
- the W-beam guardrail element may be flattened vertically rather than horizontally.
- Still another advantage may be that a tensile and resistive coupling may be provided for connecting an end of the W-beam guardrail element to a terminal support post.
- the components of the system that provide the tensile connection of the guardrail beam to the terminal support post may enable the guardrail beam to remain secured after an end-on or re-directive impact.
- the system may remain in tension during both types of impacts.
- Still another advantage may be that the tension is released when the system is impacted in the reverse direction near the terminal end, however. The releasing of tension in the guardrail element for reverse direction impacts prevents vehicle instability and excessive deceleration
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Description
- The present invention relates generally to safety treatment for the ends of W-beam guardrails; and more particularly, to a tensioned guardrail terminal for dissipating impact energy of a car colliding with the end of the W-beam guardrail in an end-on or re-directive impact.
- Along most highways there are hazards that can be a substantial danger to drivers of automobiles if the automobiles leave the highway. To reduce the severity of accidents due to vehicles leaving a highway, guardrails are provided. The guardrails are installed such that the beam elements are in tension to aid in re-directive type impacts. Guardrails must be installed, however, such that the terminal end of the guardrail facing the flow of traffic is not a hazard. Early guardrails had no proper termination at the ends, and it was not uncommon for impacting vehicles to become impaled on the guardrail causing intense deceleration of the vehicle and severe injury to the occupants. In some reported cases, the guardrail penetrated directly, into the occupant compartment of the vehicle fatally injuring the occupants.
- Upon recognition of the problem of proper guardrail termination, guardrail designs were developed that used box beams and W-beams that allow tapering of the end of the guardrail into the ground. Such designs eliminate any spearing effect. While these end treatments successfully removed the danger of the vehicle being penetrated in a head-on collision, it was discovered that these end treatments operate in a ramp-like fashion and may induce launching of the vehicle causing it to become airborne for a considerable distance with the possibility of roll over.
- In search for better end treatments, improved energy absorbing end treatments for W-beam guardrail elements were developed. For example, an extruder terminal was developed and typically includes a bending structure that squeezes the guardrail into a flat plate and then bends it about a circular arc directed away from the impacting vehicle. Example extruder terminal products include the ET 2000™ and the ET-PLUS™ offered by Trinity Highway Products. Other extruder terminal products include the SKT 350™ and FLEAT 350™ offered by Road Systems, Inc. An end treatment of a guardrail safety system according to the preamble of claim 1 is known from
WO 00/32878 A - All of these energy absorbing systems use a cable to connect the first W-beam guardrail segment to the first post in the system. The cable provides tension in the guardrail beam element for a redirective hit along the length-of-need portion of the guardrail. A number of cable releasing posts have also been developed for use in these terminals. The cable release posts are intended to release the cable anchor and, thus, release the tension in the system when the post is impacted in either of a forward (end-on) or reverse direction. Such systems are not able to remain in tension during end-on and reverse-direction type impacts.
- The present invention provides a new and improved end treatment for highway guardrails.
- In accordance with the present invention, there is provided an end treatment of a guardrail safety system according to Claim 1. Technical advantages of particular embodiments of the present invention include a guardrail end treatment that dissipates impact energy through the compression of a W-beam guardrail element. Thus, one advantage may be that the guardrail end treatment is energy absorbing. Another advantage may be that the end treatment forces the W-beam guardrail element through a flattening structure that squeezes the guardrail into a relatively flat plate. Specifically, the guardrail end treatment dissipates impact energy of a vehicle colliding with an end of a guardrail by flattening a portion of the guardrail. An end of the W-beam guardrail element extends through the flattening structure and tapers to the ground. The W-beam guardrail element is secured to the ground in tension. The components of the system that provide the tensile connection of the guardrail beam to the terminal support post enables the guardrail beam to remain secured after an end-on or re-directive impact. Thus, the system remains in tension during both types of impacts. An advantage may be that the tension is released when the system is impacted in the reverse direction near the terminal end, however. The releasing of tension in the guardrail element for reverse direction impacts prevents vehicle instability and excessive deceleration.
- Other technical advantages will be readily apparent to one skilled in the art from the following figures, descriptions and claims. Moreover, while specific advantages have been enumerated above, various embodiments may include all, some or none of the enumerated advantages.
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FIGURE 1 illustrates a top view of an exemplary guardrail safety system that incorporates certain aspects of the present invention; -
FIGURE 2 illustrates a side view of a terminal portion of a guardrail system that incorporates certain aspects of the present invention; -
FIGURE 3 illustrates a side view of an exemplary embodiment of an end treatment in the terminal portion of a guardrail system, in accordance with a particular embodiment of the present invention; -
FIGURES 4A and 4B illustrate a side view and a profile view, respectively, of a modified guardrail beam that incorporates certain aspects of the present invention; -
FIGURES 5A-5C illustrate an exemplary weakened support post suitable for use in a guardrail safety system, in accordance with a particular embodiment of the present invention; -
FIGURES 6A-6C illustrates another exemplary weakened support post suitable for use in a guardrail safety system, in accordance with a particular embodiment of the present invention; -
FIGURES 7A-7C illustrates an exemplary unmodified support post suitable for use in a guardrail safety system, in accordance with a particular embodiment of the present invention; -
FIGURES 8A and 8B illustrate an exemplary embodiment of a terminal support post for use in a guardrail safety system, in accordance with a particular embodiment of the present invention; -
FIGURES 9A-9C illustrate various components of a resistive, tensile connection for connecting a guardrail beam to a terminal support post, in accordance with a particular embodiment of the present invention; -
FIGURES 10A and 10B illustrate an exemplary resistive, tensile connection for connecting a guardrail beam to a terminal support post, in accordance with a particular embodiment of the present invention; -
FIGURES 11A and 11B illustrate an exemplary strut for use in a guardrail safety system, in accordance with a particular embodiment of the present invention; and -
FIGURE 12 illustrates an example of a resistive, tensile connection for connecting a guardrail beam to a terminal support post, which does not form part of the present invention. - Existing guardrail end treatments have proven to be unsafe for some collision conditions that happen on the highway, sensitive to installation details, and/or very costly. However, the end treatment described below is a safety treatment for the ends of a W-beam guardrail that provides a higher level of performance over a wider range of collision conditions and reduces end treatment costs and the number of injuries and deaths associated with guardrail terminal accidents. The described system maintains the tension in the guardrail beam element during both end-on and re-directive type impacts. When the system is impacted in the reverse direction near the terminal end, however, the anchorage system may release to prevent vehicle instability or excessive deceleration.
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FIGURE 1 illustrates aguardrail safety system 100 that incorporates certain aspects of the present invention.Guardrail system 100 may be installed adjacent a roadway, to protect vehicles, drivers and passengers from various obstacles and hazards, and prevent vehicles from leaving the roadway during a traffic accident or other hazardous condition. Guardrail systems that incorporate aspects of the present invention may be used in median strips or shoulders of highways, roadways, or any path that is likely to encounter vehicular traffic. -
Guardrail system 100 includes aguardrail beam 102 andsupport posts 104 that anchorguardrail beam 102 in place along the roadway. In a particular embodiment,guardrail beam 102 may include multiple 12-gauge W-beam rail elements of a length on the order of approximately 3.8 m (12.5 feet) or 7.6 m (25 feet). The guardrail beam sections may be mounted at a height of on the order of approximately 0.69-0.79 m (27 to 31 inches) with rail splices positioned mid- span between the support posts 104.Guardrail beam 102 and the terminal end ofguardrail beam 102, specifically, are illustrated in more detail inFIGURES 4A and 4B and will be described below. -
Guardrail beam 102 is attached to supportposts 104 with connectors that may include, in particular embodiments, slotted countersunk bolts such as, for example, 16 mm (5/8-inch) diameter by 38 mm (1-1/2-inch) long flat slot machine screws. Oversized guardrail nuts may be used on the back side of thesupport post 104. - Support posts 104 may be embedded in the ground, a concrete footing, or a metal socket. Support posts 104 may be made of wood, metal, plastic, composite materials, or any combination of these or other suitable materials. It is also recognized that each
support post 104 withinguardrail system 100 need not necessarily be made of the same material or include the same structural features. Furthermore, the cross-section ofsupport posts 104 may be any engineered shape suitable for releasably supportingguardrail beam 102. Such cross-sectional shapes may include, but are not limited to, square, rectangular, round, elliptical, trapezoidal, solid, hollow, closed, or open. -
Guardrail system 100 is intended to keep errant vehicles from leaving the roadway during a crash or other hazardous situation. In many instances,guardrail 100 is installed between a roadway and a significant hazard to vehicles (e.g., another roadway, a bridge, cliff, etc.). Therefore,guardrail system 100 should be designed to withstand a significant impact from a direction generally perpendicular to the roadway, without substantial failure. It is this strength that allowsguardrail system 100 to withstand the impact, and still redirect the vehicle so that it is once again traveling generally in the direction of the roadway. - However, testing and experience has continuously shown that guardrail systems may actually introduce additional hazards to the roadway and surrounding areas. This is particularly true with respect to vehicles that impact the guardrail system adjacent its terminal section, in a direction generally parallel to the roadway. For example, if the guardrail system were rigidly fixed in place during a crash, serious injury and damage may result to the errant vehicle, its driver and passengers. Accordingly, many attempts have been made to minimize this added risk. Such methods generally include the use of terminal portions that are tapered from the ground up to effectively reduce the impact of head on collisions and to create a ramp- like effect that causes vehicles to go airborne during a crash. Other methods include breakaway cable terminals (BCT), vehicle attenuating terminals (VAT), SENTRE end treatments, breakaway end terminals (BET) and the breakaway support posts of
U.S. Patent No. 6,398,192 ("192 Patent"). Many-such terminals, supports, end treatments and the like are commercially available from various organizations. Examples include the HBA post by Exodyne Technologies and Trinity Industries, and a breakaway support post similar in configuration to that described in the 192 Patent. - Referring again to
FIGURES 1 and 2 ,guardrail system 100 includes oneterminal post 106 and seven support posts 104. Collectively, this configuration forms aterminal section 108 ofguardrail system 100. As shown,terminal section 108 is employed in a preferred embodiment as an end terminal for aconventional guardrail assembly 100. - Although
FIGURE 1 is illustrated with dimensions and depicts one exemplary embodiment, it is understood that the dimensions ofguardrail system 100 may vary depending on the nature of the roadside hazard being shielded. As illustrated, eachterminal section 108 has a length on the order of approximately 10.7 m (35 feet). However, the dimensions ofterminal section 108 may vary as needed. Additionally, the length of the length-of-need portion of the system may of any appropriate length required by the conditions of the roadway. -
Terminal section 108 may be installed either parallel to the roadway or at an angular departure from the roadway, as shown best inFIGURE 1 . Additionally, while theterminal section 108 at one end of the guardrail safety system may be flared, theterminal section 108 at the opposite end of the system may not be flared, in certain embodiments. For example, in the embodiment depicted inFIGURE 1 , an upstreamterminal section 108 is flared while a downstreamterminal section 108 is not flared. Specifically, the upstreamterminal sections 108 is flared away from the roadway in a substantially linear manner while the downstreamterminal section 108 remains substantially parallel to the roadway. In other embodiments, bothterminal sections 108 may be flared or unflared in a similar manner. Additionally, it is recognized that other configurations may be used forterminal sections 108. For example, one or both ofterminal sections 108 may be installed at a parabolic flare away from the roadway. A parabolic flare may be accomplished by increasing the offset of each support post in a generally parabolic progression as the terminal portion proceeds upstream. - Where incorporated, positioning of one or more of
terminal sections 108 at a flared or angular departure away from the roadway may permit theterminal sections 108 to perform a gating function by facilitating movement of the impacting vehicle to the side of the rail opposite the roadway as the vehicle progresses. In a particular embodiment whereterminal section 108 is linearly flared,terminal section 108 may be flared back at an angle of approximately 6 to 7 degrees from the non-terminal portion of the guardrail. Where support posts 104 ofterminal section 108 are spaced apart at intervals of approximately 1.9 m (75 inches), the mostdownstream post 104 ofterminal section 108 may be approximately 0.23 m (9 inches) offset from a line tangent to the non-terminal portion of the guardrail, in a particular embodiment. Moving toward the upstream end ofterminal section 108, the next four successive support posts 104 may be 0.48, 0.74, 0.99 and 1.22 m (19, 29.25, 39, and 48 inches) offset from a line tangent to the non-terminal portion of the guardrail, in this embodiment.Terminal post 106, which may be positioned directly belowguardrail beam 102, may be approximately 1.19 m (47 inches) offset from a line tangent to the non-terminal portion of the guardrail, in the described embodiment. - As shown better in
FIGURE 2 ,terminal section 108 includes anend treatment 110.End treatment 110 includes a flatteningchute 112 and a frontstriking plate 114.End treatment 110 and flatteningchute 112, specifically, is mounted onto afirst post 104 by fasteners such as bolts. The purpose ofend treatment 110 is to dissipate impact energy of the vehicle without creating a dangerous condition such as causing the vehicle to roll-over or allow theguardrail 102 to spear the vehicle or the occupant compartment of the vehicle. -
Guardrail beam element 102 feeds into aninlet 116 at a downstream end of flatteningchute 112.Guardrail beam element 102 is disposed within flatteningchute 112 and extends the length of flatteningchute 112.Guardrail beam element 102 exits anoutlet 118 at an upstream end of flatteningchute 112. As will be described in more detail with regard toFIGURE 3 , the dimensions of flatteningchute 112 results in a terminal portion of theguardrail beam 102 tapering to the ground. The portion ofguardrail beam element 102 exitingoutlet 118 is flattened vertically such that the terminal portion ofguardrail beam element 102 resembles a stack of four flat plates. - A
terminal post 106 secures the terminal end ofguardrail beam element 102 to the ground and placesguardrail beam element 102 in tension. As will be described in more detail with regard toFIGURES 8A and 8B and10A and 10B , the coupling ofguardrail beam element 102 toterminal post 106 enablesguardrail beam element 102 to remain secured in tension toterminal post 106 after either of an end-on or redirective impact by a vehicle leaving the roadway. However, the components effecting the tensile coupling enables the tension inguardrail beam element 102 to be released when the system is impacted in the reverse direction near the terminal end. - The releasing of tension in the guardrail element for reverse direction impacts prevents vehicle instability and excessive deceleration.
-
FIGURE 3 illustrates an exemplary embodiment ofend treatment 110 in greater detail. As described above,end treatment 110 includes a flatteningchute 112 and a frontstriking plate 114. Flatteningchute 112 and frontstriking plate 114 are coupled to anextruder 120.Extruder 120 surrounds the upstream portion ofguardrail beam member 102 and is made up of an upper,U-shaped channel member 122 and a lower,U-shaped channel member 124, which are secured in a spaced relation to one another bystrap plates 126. The vertical distance betweenchannel members guardrail beam 102 is inserted into the channel created byextruder 120. For example, whereguardrail beam 102 comprises a 12-gauge W-beam rail element having a vertical dimension of approximately 0.31 m (12.25 inches), the distance between the top ofchannel member 122 and the bottom ofchannel 124 may be approximately 0.36 m (14 inches), in a particular embodiment. - Front
striking plate 114 is secured by welding to extruder 120 ofend treatment 110. Frontstriking plate 114 may be vertically elongated, in particular embodiments. Thus, frontstriking plate 114 may extend both above and belowextruder 120 to permit frontstriking plate 114 to be easily engaged by either the high bumper of trucks, SUV's, and other taller vehicles and the low set bumpers of smaller cars impacting in a frontal manner. Frontstriking plate 114 is also positioned so as to engage the vehicle frame or rocker panel to reduce vehicle intrusion when the upstream end ofend treatment 110 is impacted by a vehicle in a sideways manner. - Flattening
portion 112, which is mounted toextruder 120, may be constructed from four metal plates, in a particular embodiment. The four metal plates may be cut and/or bent and then welded together to form the desired configuration. Alternatively, flatteningportion 112 may be formed from more than four pieces or from a single piece of metal that is cut and bent into the desired configuration. When flatteningportion 112 is assembled, flatteningportion 112 may form an enclosed structure that houses a terminal portion ofguardrail beam 102. - In the illustrated embodiment, flattening
portion 112 includes three sections. The most downstream portion of flatteningportion 112 includes athroat 128. The vertical dimension ofthroat 128 is greater at the downstream end and decreases as it approaches the upstream end ofend treatment 110. For example, in a particular embodiment, the vertical dimension ofthroat 128 may be approximately 0.36 m (14 inches) wide at the downstream end and approximately 0.11 m (4.5 inches) wide at the upstream end. The horizontal length ofthroat 128 may be within a range of approximately 0.28 to 0.33 m (11 to 13 inches). - In a particular embodiment, the slope of a
lower edge 132 may be greater than the slope of anupper edge 130. The increased slope oflower edge 132 may aid in the flattening ofguardrail beam 102 during an impact. For example, in a particular embodiment,upper edge 130 may slope upward at an angle of approximately 11 degrees from the horizontal, andlower edge 132 may slope downward at an angle of approximately 13 degrees from the horizontal. In still other embodiments, the slope ofupper edge 130 andlower edge 132 may be substantially the same. Thus, in a particular embodiment,upper edge 130 andlower edge 132 may symmetrically mirror one another. In still other embodiments, one oftop edge 130 andlower edge 132 may be aligned with the horizontal (substantially parallel with the roadway) while the other oftop edge 130 andlower edge 132 slopes upward or downward, respectively. - A
mid portion 134 extends from the upstream end ofthroat 128 and slopes toward the ground. Specifically,mid portion 134 is configured to transitionguardrail beam element 102 from a height above the ground level that is appropriate for redirecting an impacting vehicle (0.79 m (31 inches), in a particular embodiment) to a height that is proximate the ground's surface. Thus,mid portion 134 extends from a vertical distance associated withthroat 128 at a downstream end to approximately ground level at an upstream end. In a particular embodiment, where the horizontal length ofmid portion 134 is approximately 0.48 m (18.75 inches),mid portion 134 may slope at an angle of approximately 38 degrees from the horizontal. -
Mid portion 134 also provides a channel through which a terminal portion ofguardrail beam element 102 is disposed. In a particular embodiment, the vertical dimension of the channel withinmid portion 134 may be approximately 0.11 m (4.5 inches) (similar to the width ofthroat 128 at the upstream end). The dimensions of the channel withinmid portion 134 may remain substantially constant such that the vertical dimension of the channel withinmid portion 134 at the downstream end is the substantially the same as the vertical dimension of the channel withinmid portion 134 at the upstream end. - A third portion of flattening
portion 112 includesoutlet portion 136.Outlet portion 136 extends from the upstream end ofmid portion 134.Outlet portion 136 is disposed proximate the grounds' surface and is in substantial alignment with the grounds' surface.Outlet portion 136 also forms a channel through which the terminal end ofguardrail beam element 102 exits the flatteningchute 112. In a particular embodiment, the vertical dimension of the channel withinoutlet portion 136 may be approximately 0.11 m (4.5 inches) (similar to the vertical dimension of the channel within mid portion 134). The dimensions of the channel withinoutlet portion 136 may remain substantially constant such that the vertical dimension of the channel at the downstream end ofoutlet portion 136 is substantially the same as the vertical dimension of the channel at the upstream end ofoutlet portion 136. In a particular embodiment, the horizontal length ofoutlet portion 136 may be approximately 0.13-0.18 m (5-7 inches). - As stated above with regard to
Figure 2 ,guardrail beam member 102 is disposed within and extends throughout the length of flatteningportion 112. Specifically, guardrail beam member feeds into aninlet 116 at a downstream end of flatteningchute 112.Guardrail beam element 102 traverses the length of flatteningchute 112 and exits anoutlet 118 at an upstream end of flatteningchute 112. Thus, a terminal end of the W-beam guardrail element extends through the flattening structure. The slope ofmid portion 134 toward the ground in the upstream direction results inguardrail beam element 102 being gradually transitioned toward the ground over the length of flatteningportion 112. After exiting theoutlet 118,guardrail beam element 102 is secured to aterminal post 106 at ground level. - During an end-on or oblique end-on collision of a vehicle with front
striking plate 114,end treatment 110 may be displaced in a downstream direction and downstream portions ofguardrail beam element 102 may be forced into thedisplaced end treatment 110. During such a collision, extruder 120 functions as a guide to guide guardrail beam element into flatteningportion 112.Extruder 120 includesguides 138 that prevent shaving of the W-beam guardrail element 102 by ends ofextruder 120 asextruder 120 moves along the length of theguardrail beam element 102 during a collision. Theguides 138 accommodate any irregularities or bumps inguardrail beam element 102 to ensure proper feeding ofguardrail beam element 102 into flatteningportion 112. - As
end treatment 110 moves alongguardrail beam element 102 and downstream portions ofguardrail beam element 102 are forced into flatteningportion 112,guardrail beam element 102 is flattened vertically. Portions ofguardrail beam element 102 exitingoutlet 118 of flattening portion 1 12 are flattened into what may appear to be four vertically stacked plates. For example, where the vertical dimension ofguardrail beam element 102 is approximately 0.31 m (12.25 inches) andthroat portion 134 of flatteningportion 112 is approximately 0.11 m (4.5 inches), the vertical dimension of the flattened portion ofguardrail beam element 102 may be less than approximately 0.11 m (4.5 inches). As this flattening process occurs, substantial energy is dissipated slowing the impacting vehicle. - To aid in initial flattening of
guardrail beam element 102 for coupling toterminal support post 106, a terminal end ofguardrail beam element 102 may be modified.FIGURES 4A and 4B illustrate a modifiedguardrail beam element 200 in accordance with one embodiment. As shown inFIGURE 4A , theguardrail beam element 200 includes a slottedzone 202 at the upstream end of the terminal portion ofguardrail beam element 200. In a particular embodiment, slottedzone 202 comprises a series of slots longitudinally disposed in theguardrail beam element 200. The use of three slots has proven effective in testing models of guardrails constructed similar toguardrail safety system 100. Slottedzone 202 may initiate at aterminal end 203 ofguardrail beam element 200 and extend a desired distance downstream. The horizontal length of slottedzone 202 may vary depending on the horizontal length ofend treatment 110. It may be desirable for slottedzone 202 to include the portion ofguardrail beam element 200 that is coupled toterminal post 106 and the portion ofguardrail beam element 200 that traverses through flatteningportion 112. Generally, slottedzone 202 may extend from the terminal, upstream end ofguardrail beam element 200 to some distance between the first and second support posts 104. Where, for example, the dimensions of theterminal section 108 ofguardrail system 100 are similar to those illustrated inFIGURE 1 , slottedzone 202 may extend approximately 2.0-2.2 m (80-85 inches) from the terminal end ofguardrail beam element 200. - The placement of the slots in slotted
zone 202, according to a particular embodiment, may be better understood with reference to the cross-section for a typical W-beam guardrail 200 as shown inFIGURE 4B . Avalley 204 is positioned between upper andlower peaks 206 and is formed at the intersections ofinclined web portions 208.Edge members 210 laterally out lie eachpeak 206. Highly preferred placement for the slots is proximate each peak 206 and thevalley 204. Thus, in the illustrated embodiment ofFIGURE 4A , first andsecond slots 212 are placed in the first andsecond peaks 206, respectively. Athird slot 214 is placed invalley 204.Slots guardrail beam element 200 to be flattened. In a preferred embodiment, the entire vertical dimension of each peak 206 andvalley 204 may be removed. Effective sizes forslots 212 have been found to be approximately 0.013 m (0.5 inches), as measured vertically. An effective size forslot 214 has been found to be approximately 0.019 m (0.75 inches), as measured vertically. Thus, in a particular embodiment,slots 212 may have a width on the order of 0.013 m (0.5 inches) and extend approximately 2.06-2.08 m (81-82 inches).Slot 214 may have a width on the order of approximately 0.019 m (0.75 inches) and extend approximately 2.06-2.08 m (81-82 inches). The provided dimensions are for example purposes only, however. Any dimensions may be used forslots guardrail beam 200 to be flattened into four vertically stacked plates throughout the terminal end ofguardrail beam element 200. - It is recognized that the configuration and dimensions of any of the above-described elements within
guardrail system 100 may vary as desired. - Returning to
FIGURES 1 and 2 , following the initial end-on impact of a vehicle withend treatment 110 and the initiation of the displacement ofend treatment 110 in a downstream direction, the impacting vehicle andend treatment 110 may engage one or more support posts 104. Where the support posts 104 comprises steel yielding support posts that are modified at ground level, the impacted support posts 104 may releaseguardrail beam element 102 as they are impacted and bent toward the ground. Thus, support posts 104 that are impacted during the collision may be displaced, in certain embodiments, such that they do not pose a hazard to the impacting vehicle. Althoughguardrail beam 102 may be released from impacted support posts 104, portions ofguardrail beam element 102 downstream from the impact may remain in substantially their original position relative to the ground's surface. Further, becauseguardrail beam 102 remains coupled toterminal post 106 during an end-on or re-directive impact,guardrail beam 102 remains in tension. This extends the range of acceptable performance ofguardrail safety system 100. - The tension in
guardrail beam 102 may also be retained in this manner whenguardrail system 100 is subject to a re-directive impact in the length of need portion ofguardrail system 100. For example, when an impacting vehicle traveling in a direction substantially parallel to the downstream direction ofguardrail system 100 leaves the roadway and impactsguardrail system 100, anysupport posts 104 impacted by the vehicle may operate to releaseguardrail beam element 102 as they are impacted. Modified support posts 104 may be bent toward the ground such that the support posts 104 are displaced and do not pose a hazard to the impacting vehicle. Because the tension inguardrail beam 102 is maintained,guardrail beam element 102 continues to operate to redirect the vehicle back onto the roadway even after one or more support posts are released fromguardrail beam element 102. -
FIGURES 5A-5C, 6A-6C, and 7A-7C illustrate example embodiments of support posts that may be used in conjunction withguardrail system 100 ofFIGURE 1 . Specifically,FIGURES 5A-5C illustrate an exemplary weakened support post that may be used as a first support post 500 (after the terminal support post 106) in theterminal section 108 ofguardrail safety system 100.FIGURES 6A-6C illustrate an exemplary weakenedsupport post 600 that may be used throughoutterminal section 108 and other portions ofguardrail safety system 100.FIGURES 7A-7C illustrate astandard line post 700 that may be used in certain portions ofguardrail safety system 100. AlthoughFIGURES 5A-5C, 6A-6C, and 7A-7C illustrate three distinct embodiments, respectively, like reference numerals have been used to identify parts common to the three embodiments. - As illustrated, support posts 500, 600, and 700 include elongate, continuous structural members and are each of a standard wide flange configuration. Each support post includes two
flanges 502, that are generally parallel with one another, and in spaced apart relation from one another. Aweb 504 forms the coupling betweenflanges 502. In a preferred embodiment,flanges 502 include a generally identical configuration ofboltholes 506 andcutouts 508, therein. - With regard to the wide flange shape used as a guardrail post, the cross section is typically shaped like the letter "H". The cross section has two major axes for bending. The "weak" axis generally refers to a central axis that extends through the web and is perpendicular to the flanges. The "strong" axis generally refers to a central axis that is perpendicular to the web and parallel to the planes of the flanges. The weak axis for a conventional installation of guardrail extends generally transversely to the road. The strong axis extends generally along the roadway.
- In the illustrated embodiment of
FIGURES 5A-5C, 6A-6C, and 7A-7C the wide flange is a standard W6x8.5, which is commonly used in fabricating support posts for guardrail installations. A standard W6x8.5 wide flange may have a nominal six-inch depth and weigh eight and one-half pounds per foot. In fact, one advantage of the present invention is the ability to re-use existing, standard equipment to fabricate, modify, and installsupport post 500, without substantial modification to the equipment. Those of ordinary skill in the art will recognize that wide flange beams may be available in many different sizes. For example, a wide flange having a six-inch depth and weighing nine pounds per foot may also be used. Such a wide flange is referred to as a W6x9 wide flange. However, a W6x9 wide flange and a W6x8.5 wide flange are considered equivalent in the trade. The terms "W6x8.5 wide flange" and "W6x9 wide flange" are intended to refer to all sizes and configurations of guardrail posts that may be referred to as "W6x9" by a person of ordinary skill in the art. In addition, persons skilled in the art recognize other names used for wide flanges include but are not limited to "I-beam," "H-beam," "W-beam," "S-beam," "M-beam," or the term "shape" may be substituted for "beam." - Support posts 500, 600, and 700 have a length in a range of approximately 72 and 73 3/8 inches, in particular embodiments, and include an
upper portion 510 and alower portion 512. Amid portion 514 couplesupper portion 510 withlower portion 512.Upper portion 510 includes twoboltholes 506 that are adapted to receive connectors for the installation of a guardrail beam (e.g., guardrail beam 102) upon the support post.Lower portion 512 is suitable for installation below grade, as part of a guardrail support system. Bolt holes 506 include a standard configuration that allow for the installation of widely used guardrail beams, upon the respective support post. In general, bolt holes 506 align with the center of the guardrail beam, and maintain the center of the guardrail beam approximately 0.76 m (30 inches) above grade. However, the number, size, location and configuration ofboltholes 506 may be significantly modified, within the teachings of the present invention . - Support posts 500 and 600 are each modified to include a relatively "weak" axis W, and a relatively "strong" axis S. Support posts 500 and 600 are normally installed along a roadway such that weak axis W is generally perpendicular to the direction of traffic, and strong axis S is generally parallel to the direction of traffic. Accordingly, support posts 500 and 600 are typically able to withstand a significant impact (e.g., with a car traveling at a high rate of speed) about the strong axis S without substantial failure. However, support posts 500 and 600 are intentionally designed such that failure will more readily occur in response to an impact about the weak axis W. Stated differently, support posts 500 and 600 exhibit adequate strength in the lateral direction but sufficiently low strength in the longitudinal direction.
- Accordingly, if a vehicle impacts
end treatment 110 "end-on", support posts 500 and 600 will tend to fail (e.g., buckle), while allowing the vehicle to decelerate as it impacts consecutive support posts. However, if a vehicle strikesguardrail system 100 along the face of and at an angle toguardrail beam 102, support posts 500 and 600 will provide sufficient resistance (strength) to redirect the vehicle along a path generally parallel withguardrail beam 102. -
Mid portions 514 ofsupport posts cutouts 508, which are configured to further weaken the support posts about the weak axis W, to more readily allow for failure due to impact from a vehicle along that direction.Cutouts 508 are positioned withinmid portion 514 to weaken the support posts about weak axis W, adjacent grade (when installed). This will accommodate failure of the support posts approximately at grade, allowing support posts 500 and 600 to "fold" over from the point of failure, upward. Sincelower portion 512 is below grade, it is not expected that the ground, orlower portion 512 of the support post will appreciably deflect during an impact. - Since
cutouts 508 are intended to occur approximately at grade, and the center of bolt holes 506 are intended to occur 0.76 m (30 inches) above grade, bolt holes 506 occur 30 inches abovecutouts 508, in the illustrated embodiment. It will be recognized by those of ordinary skill in the art that the size, configuration, location and number of bolt holes, cutouts, and their relationship with each other, may be varied significantly within the teachings of the present invention. The overall length of the support posts, and their respective upper, lower and mid portions may vary significantly, within the teachings of the present invention. For example, in other embodiments,cutouts 508 may occur below grade or above grade. The depth ofcutouts 508 below grade should not exceed an amount that will prevent the support posts from failing at or near the location ofcutouts 508. At some depth below grade, the surrounding earthen (or other) material will reinforcelower portion 512 of the support posts to an extent that will no longer accommodate such failure to occur. - The height of
cutouts 508 above grade should not exceed a point at which the support post will fail atcutouts 508, and leave a "stub" above grade which can snag vehicles, and otherwise cause excessive injury and/or excessive damage. Such a stub could be detrimental to the redirective effect of the guardrail system in which the support post is operating. - The vertical dimension of a
cutout 508 is limited based upon the horizontal dimension ofcutout 508. For example, a ratio of the vertical dimension of any particular cutout may be equal to, or less than three times the horizontal dimension. Alternatively, the ratio may be limited to two times the horizontal dimension. In the illustrated embodiments, the ratio is 1:1, sincecutout 508 is generally a circular opening in the support post. The smaller the vertical dimension of the cutout, the more precisely the designer may dictate the point of failure along the vertical length ofsupport posts - Various configurations of
cutouts 508 are available to a designer ofsupport posts cutouts 508 may comprise square, rectangular, triangular, oval, diamond shaped, or practically any other geometric configuration, and still obtain some or all of the benefits described herein. - The horizontal orientation of
cutouts 508 withinflanges 502 may also be altered significantly, within the teachings of the present invention. In the illustrated embodiments ofFIGURES 5A-5C and 6A-6C , the centerline ofcutouts 508 is located approximately one inch from the centerline offlanges 508. However, in alternative embodiments,cutouts 508 may be located closer to such edges, or further from such edges. In one embodiment,cutouts 508 may be configured such that they extend all the way to the edge of the flange, such that there is a break in material beginning at the edge. In this manner, a traditional punch could be employed at the edge, to form a semi-circular opening that extends to the edge of the flange. - Alternatively, a sawcut could be employed from the outer edge of the flange, and extending inward, to form
cutouts 508. In this manner, the sawcut would form the starting point of the likely point of failure along the weak axis of the support post. Rather than a sawcut, a similar configuration may include a slot in which the longest dimension extends horizontally through the flange. Such a slot may begin or terminate at the edge of the flange, or otherwise be disposed completely within the material of the flange. - As stated above,
FIGURES 5A-5C specifically illustrate aguardrail support post 500 that may be used as the first support post (after the terminal support post 106) in aguardrail system 100. Where an end treatment such asend treatment 110 is incorporated intoguardrail safety system 100,support post 500 may be modified to support anend treatment 110. Specifically,support post 500 includesadditional boltholes end treatment 110 to supportpost 500. In the particular illustrated embodiment,boltholes boltholes 506 andcutouts 508. It is recognized, however, that the provided dimensions ofboltholes end treatment 110 to supportpost 500. In contrast to supportpost 500, support posts 600 and 700 do not includeadditional boltholes guardrail system 100 that are not directly supportingend treatment 110. - Although W6x8.5 wide flanges are described above and illustrated within this specification, it should be recognized by those of ordinary skill in the art that practically any size guardrail support post may be weakened as described above. The size, weight and configuration of the support post are just a few factors to be considered to determine the appropriate location of cutouts, to allow yielding along the weak axis while maintaining sufficient strength along the strong axis to redirect impacting vehicles. Further, although it may be desirable for at least a portion of the support posts in the
guardrail safety system 100 to include weakened support posts such as support posts 500 and 600 ofFIGURES 5A-5C , supports posts may also include conventional, unmodified support posts or other structural members suitable for supporting a guardrail beam.FIGURES 7A-7C illustrate such an unmodified support post.Support post 700 does not includecutouts 508 and may comprise standard line posts such as unmodified W6x8.5 posts or any other support post of an appropriate size, weight and configuration. - Although certain of the support posts may be configured to release the guardrail beam element upon vehicular impact, it may be desirable for a terminal support post to remain coupled to guardrail beam even after an end-on or re-directive impact.
FIGURES 8A and 8B illustrate an example embodiment of aterminal support post 800 that may be used in conjunction withguardrail system 100 ofFIGURE 1 . Referring toFIGURE 1 ,terminal support post 800 is the first terminal support post at the upstream end ofterminal section 108.FIGURE 8A is a side view ofterminal support post 800, andFIGURE 8B is a front view of the sameterminal support post 800. - In particular embodiments,
terminal support post 800 is releasably coupled toguardrail beam 102 such thatguardrail beam 102 and provides positive anchorage ofguardrail beam 102 to react to tensile loads onguardrail beam 102 to redirect a vehicle impacting laterally along the length ofguardrail beam 102. Various components are used to effect the coupling ofguardrail beam 102 toterminal support post 800 such thatguardrail beam 102 remains coupled toterminal support post 800 whenguardrail system 100 is struck by an impacting vehicle in an end-on or re-directive type impact. As a result, guardrail beam element remains supported in tension even after such an impact. However, whenguardrail system 100 is struck by an impacting vehicle in the reverse direction, the tensile coupling ofguardrail beam 102 will be released fromterminal support post 800 to prevent vehicle instability and excessive vehicular deceleration. - In the illustrated embodiment,
terminal support post 800 includes astructural member 802 of an I-beam configuration.Structural member 802 includes a pair offlanges 804 interconnected by acentral web 806. In a currently preferred embodiment, thebeam member 802 comprises a W 6x15 steel post member. A pair ofrectangular side plates 808 are affixed opposite sides ofstructural member 802. Preferably,side plates 808 are secured by welding to each offlanges 804. - A connector assembly is used to couple
structural member 802 to the guardrail beam member. The connector assembly is configured such that the coupling of the structural member and the terminal portion of the guardrail beam is maintained during an end-on or re-directive impact by a vehicle. However, the connector assembly is configured to release the coupling during a reverse-direction impact. In a particular embodiment, the connector assembly comprises a plurality of stacked rectangular plates that are aligned to receive the terminal portion of the guardrail beam. For example, the connector assembly may include a stack of three plates: aflange plate 810, akeeper plate 816, and awasher plate 824. - A
flange plate 810 is secured betweenside plates 808.Flange plate 810 is preferably a unitarily formed piece that is secured by welding tostructural member 802 and eachside plate 808.Flange plate 810, as best shown inFIGURE 9A , includes a rectangular plate with a V-shaped cut-out 812 at the center of anupper edge 813 offlange plate 810. In the illustrated embodiment,flange plate 810 has a length of approximately 0.13 m (5 inches) and a width of approximately 0.15 m (6 inches). The thickness offlange plate 810, as best shown inFIGURE 8B , may be approximately 0.025 m (1 inch). - V-shaped
slot 812 is centered along the horizontal width offlange plate 810 and has a vertical length of approximately (0.03) 1 inch and a horizontal width of approximately 0.04 m (1 3/4 inches). Therounded bottom 814 of V-shapedslot 812 has a diameter of approximately 0.03 m (1 1/4 inches). However, the described and depicted dimensions offlange plate 810 are provided for example purposes only. Although the depicted dimensions may be appropriate wherestructural member 802 includes a W6x15 steel post member, the dimensions offlange plate 810 may vary and may depend on size and dimensions ofstructural member 802. - Returning to
FIGURE 8B , akeeper plate 816 is disposed adjacent toflange plate 810. Similar toflange plate 810,keeper plate 816 is preferably a unitarily formed piece. As best shown inFIGURE 9B , keepplate 816 includes a rectangular plate with a circular shapedopening 818 proximate anupper edge 820 ofkeeper plate 816. In the illustrated embodiment,keeper plate 816 has a vertical length of approximately 0.08 m (3 1/8 inches) and a horizontal width of approximately 0.14m (5 3/8 inches).Opening 818 is centered along the horizontal width ofkeeper plate 816 and has a center that is approximately 0.02 m (7/8 inch) fromupper edge 820 ofkeeper plate 816.U-shaped opening 818 may have a diameter of approximately 0.03 m (1 1/4 inches). However, the described and depicted dimensions ofkeeper plate 816 are provided for example purposes only. Although the depicted dimensions may be appropriate wherestructural member 802 includes a W 6x15 steel post member, the dimensions ofkeeper plate 816 may vary and may depend on size and dimensions ofstructural member 802 andflange plate 810. - Returning to
FIGURE 8B , awasher plate 824 is disposed adjacent tokeeper plate 816. Similar toflange plate 810 andkeeper plate 816,washer plate 824 is preferably a unitarily formed piece. As best shown inFIGURE 9C ,washer plate 824 includes a rectangular plate with aU-shaped slot 826 at the center of theupper edge 828 ofwasher plate 824. In the illustrated embodiment,washer plate 824 has a vertical length of approximately 0.1 m (4 1/8 inches) and a horizontal width of approximately 0.14 m (5 1/2 inches). The thickness ofwasher plate 824, as best shown inFIGURE 8B , may be approximately 0.01 m (1/2 inch). -
U-shaped slot 826 is centered along the horizontal width ofwasher plate 824 and has a vertical length of approximately 0.03 m (1 1/4 inches) and a horizontal width of approximately 0.028 m (1 1/8 inches). Therounded bottom slot 826 has a diameter of approximately 0.03 m (1 1/4 inches). However, the described and depicted dimensions ofwasher plate 824 are provided for example purposes only. Although the depicted dimensions may be appropriate wherestructural member 802 includes a W 6x15 steel post member, the dimensions ofwasher plate 824 may vary and may depend on size and dimensions ofstructural member 802. - Each of
flange plate 810,keeper plate 816, andwasher plate 824 include a pair ofboltholes 830. In the illustrated embodiments,boltholes 830 are approximately 0.01 m (3/8 inches) in diameter. When assembled together, abolthole 830 of each offlange plate 810,keeper plate 816, andwasher plate 824 are in general alignment with one another. A pair of threadedbolts 832 may be secured throughboltholes 830 to secureflange plate 810,keeper plate 816, andwasher plate 824 together. Awasher 834 may be threaded onto the end of each of the threadedbolts 832 to hold the plates relative to each other. - As described above, the purpose of
terminal support post 800 is to secureguardrail beam 102 in tension.FIGURES 10A and 10B illustrate an exemplary tensile connection of aguardrail beam 1000 to a terminal support post such asterminal support post 800 depicted inFIGURES 8A and 8B . Specifically, a compressed slottedguardrail beam 1000 similar to those described above with regard toFIGURES 1, 2 , and4A-4B is coupled to aconnection plate 1002. - In the illustrated embodiment,
connection plate 1002 includes a pair ofboltholes 1004, which may be aligned with a pair of similar boltholes (not shown) in the terminal end of the compressed slottedguardrail beam 1000. A pair of threadedbolts 1006 may be threaded throughboltholes 1004 and similarly sized boltholes of guardrail beam 1000 (not shown) that are aligned withboltholes 1004. A threadednut 1008 may secure each connection ofbolts 1006 throughconnection plate 1002 andguardrail beam 1000. In a particular embodiment, theboltholes 1004 and boltholes inguardrail beam 1000 may have a diameter on the order of approximately 7/8 inch. In such an embodiment, threadedbolts 1006 may include 2 1/2 x 3/4" GR. 5 bolts. However, it is recognized that these sizes are provided as examples only. Any appropriate size of boltholes and bolts may used to secureguardrail beam 1000 toconnection plate 1002. -
Connection plate 1002 is coupled to a threadedrod 1010. In a particular embodiment, threadedrod 1010 may be welded toconnection plate 1002. As best shown inFIGURE 8B , threadedrod 1010 is threaded through V-shapedcutout 814 offlange plate 810,circular opening 818 ofkeeper plate 816, andU-shaped cutout 826 ofwasher plate 824. Anut 836 is threaded on the end of threaded rod 101 to secureguardrail beam 1000 in tension toterminal support post 800. - The presence of
nut 836 prevents withdrawal ofcable 1010 from the openings formed by V-shapedcutout 814 offlange plate 810 andU-shaped cutout 826 ofwasher plate 824. Since the opening ofkeeper plate 816 includes an enclosedcircular opening 818 rather than an open cutout in the edge of thekeeper plate 816,keeper plate 816 ensures that threadedrod 1010 is properly in place.Keeper plate 816 also adds strength to the tensile connection of threadedrod 1010 toterminal post 800.Washer plate 824, which functions as a washer betweenbolt 834 andkeeper plate 816, also adds strength to the connection. - During an end-on or redirective impact to a guardrail system incorporating the above-described features, the assembly described in
FIGURES 8A-8B ,9A-9C , and 10A-10B enables the tensile connection ofguardrail beam 1010 toterminal support post 800 to remain intact. Because theguardrail beam 1010 remains in tension,guardrail beam 1010 is able to redirect the impacting vehicle. Column buckling of the system may be eliminated and an eccentric impacting vehicle may remain in the system longer during deceleration. - In contrast, when a vehicle impacts the guardrail system in a reverse direction, the tensile connection of
guardrail beam 1010 may be released. For example, the reverse-direction impact may cause theupper edge 820 ofkeeper plate 816 directly abovecircular opening 818 to be sheared. Threadedrod 1010 is then freed from the openings formed by V-shapedcutout 812,U-shaped cutout 826, andcircular opening 818. Because the tensile connection inguardrail beam 1000 is released,guardrail beam 1000 may be controllably collapsed to prevent vehicle instability or excessive deceleration. - To further aid in the release of the tensile connection during a reverse-direction impact, a modified strut may be used to couple the terminal support post to the first adjacent support post. Such a strut is indicated as
reference numeral 140 inFIGURE 2 and is illustrated in more detail inFIGURES 11A and 11B . In the illustrated embodiment, strut 140 includes alongitudinal beam member 1112 that has been modified to include astrut plate 1114.Longitudinal beam member 1112 may include have any appropriate cross-sectional shape. The length oflongitudinal beam member 1112 is appropriate for couplingterminal support post 106 and the nextadjacent support post 104. In a particular embodiment,longitudinal beam member 1112 may include a C-channel member having a width on the order of approximately 0.15 m (6 inches) and a depth on the order of approximately 0.05 m (2 inches). - As best shown in
FIGURE 11B ,strut plate 1114 is preferably a unitarily formed piece that is secured by welding tolongitudinal beam member 1112.Strut plate 1114 includes a rectangular plate with a U-shaped cut-out 1116 at the center of theupper edge 1118 ofstrut plate 1114. In the illustrated embodiment,strut plate 1114 has a horizontal dimension of approximately 0.25 m (10 inches) and a vertical dimension of approximately 0.02 m (8 inches). The thickness ofstrut plate 1114 may be approximately 0.01 m (1/4 inch).U-shaped slot 1116 is centered along the vertical dimension ofstrut plate 1114 and has a vertical dimension of approximately 0.04 m (1 1/2 inch) and a horizontal dimension of approximately 0.14 m (5 1/2 inches). Therounded bottom 1120 ofU-shaped slot 1116 has a diameter of approximately 0.04 m (1 1/2 inches). However, the described and depicted dimensions ofstrut plate 1114 are provided for example purposes only. The dimensions ofstrut plate 1114 andlongitudinal beam member 1112 may vary. - When a vehicle impacts the guardrail system in a reverse direction,
strut 1112 andstrut plate 1114 may facilitate the release of the tensile connection between the guardrail beam and the terminal support post.Strut plate 1114 is positioned proximate the outlet end of flatteningportion 112.Strut plate 1114 operates as a ramp to facilitate the lifting of the threaded rod coupled to the guardrail beam from the V- shapedcutout 814 offlange plate 810,circular opening 818 ofkeeper plate 816, andU-shaped cutout 826 ofwasher plate 824. Because the tensile connection inguardrail beam 1000 is released,strut 1112 andstrut plate 1114 prevent instability or excessive deceleration of the impacting vehicle. As described above,FIGURES 10A and 10B illustrate an exemplary tensile connection of a guardrail beam to a threaded rod.FIGURE 12 illustrates an example of a tensile connection that may be used to couple a guardrail beam to a terminal post and which does not form part of the present invention. In the illustrated example, a slottedguardrail beam 1200 may be modified similar toguardrail beam 200 ofFIGURE 4A . Slottedguardrail beam 1200 is modified at theterminal end 1202 and is coupled to acable rod 1204. - In a particular example, again not forming part of the invention, slotted
guardrail beam 1200 may be coupled to a pair ofcable rods 1204. -
Cable rods 1204 may traverse through a flatteningportion 1206. Flatteningportion 1206 may be similar to flatteningportion 110 ofFIGURES 1-3 . Accordingly, at least a portion ofcable rods 1204 may traverse the length of flatteningportion 1206 and exit anoutlet 1206 at an upstream end of flatteningportion 1206. After exiting theoutlet 1206,cable rods 1204 may be secured to aterminal post 106 at ground level using a mechanism similar to that described above with regard toFIGURES 8A-8B ,9A-9C , and10A-10B . Technical advantages of particular embodiments of the present invention include a guardrail end treatment that dissipates impact energy through the compression of a W-beam guardrail element. Specifically, the guardrail end treatment may dissipate impact energy of a vehicle colliding with an end of a guardrail by flattening a portion of the guardrail required for deceleration of the impacting vehicle. Another advantage may be that the end treatment forces the W-beam guardrail element through a flattening structure that squeezes the guardrail into a relatively flat plate. In contrast to prior systems, the W-beam guardrail element may be flattened vertically rather than horizontally. - Still another advantage may be that a tensile and resistive coupling may be provided for connecting an end of the W-beam guardrail element to a terminal support post. The components of the system that provide the tensile connection of the guardrail beam to the terminal support post may enable the guardrail beam to remain secured after an end-on or re-directive impact. Thus, the system may remain in tension during both types of impacts. Still another advantage may be that the tension is released when the system is impacted in the reverse direction near the terminal end, however. The releasing of tension in the guardrail element for reverse direction impacts prevents vehicle instability and excessive deceleration
- Although the present invention has been described by several embodiments, various changes and modifications may be suggested to one skilled in the art. It is intended that the present invention encompass such changes and modifications as fall within the scope of the present appended claims. For example, the features described above may be used independently and/or in combination with each other or other design modifications.
Claims (12)
- An end treatment (110) of a guardrail safety system comprising:a terminal portion of a guardrail W-beam (102) comprising a downstream end and an upstream end;a flattening portion (112) having an outlet portion (136) with an outlet (118) at an upstream end and forming a channel, a vertical dimension of the channel being greater at a downstream end of the flattening portion (112) than at an upstream end of the flattening portion (112); andan impact plate (114) for engaging an impacting vehicle at an end of said guardrail W-beam (102), said impact plate (114) being coupled to the flattening portion (112);wherein said impact plate (114) and the flattening portion (112) are advanced longitudinally along the guardrail W-beam (102) in a downstream direction by a vehicle during an end-on impact, the advancement of the impact plate (114) and flattening portion (112) dissipating energy to decelerate the impacting vehicle and flattening the guardrail W-beam (102) vertically as downstream portions of the guardrail W-beam (102) are forced into the flattening portion (112);characterized in that:the terminal portion of the guardrail W-beam (102) slopes from a first vertical height appropriate for redirecting an errant vehicle to a second vertical height proximate the surface of the ground at the upstream end of the terminal portion of the guardrail W-beam (102);the guardrail W-beam (102) being installed throughout the channel of the flattening portion (112), such that a portion of the guardrail W-beam exits said outlet (118) and is flattened vertically so as to resemble a stack of plates;the end treatment comprises a terminal post (106) andthe portion of the guardrail W-beam (102) exiting the flattening portion (112) is secured in tension to said terminal post (106) at ground level such that the guardrail W-beam (102) remains connected to the terminal post (106) after an impact in the downstream direction.
- The end treatment (110) of Claim 1, wherein the flattening portion (112) comprises:a throat portion (128) receiving the terminal portion of the guardrail W-beam (102), the vertical dimension of the channel within the throat portion (128) being greater at a downstream end than an upstream end, the throat portion (128) applying a force to opposing edges of the W-guardrail beam (102) to result in the vertical flattening of the terminal portion of the guardrail W-beam (102);a mid portion (134) extending from the throat portion (128) in an upstream direction to the outlet portion (136), the mid portion (134) configured to transition the terminal portion of the guardrail W-beam (128) from the first vertical height to the second vertical height; andthe end treatment, further comprising an extruder section (120) forming a channel through which at least a portion of the guardrail W-beam (102) is disposed, the impact plate (114) being coupled to the extruder section (120).
- The end treatment (110) of Claim 1, wherein an upstream end of the guardrail W-beam (102) is coupled to a threaded rod (1010), the threaded rod (1010) coupling to the terminal support post (106).
- The end treatment (110) of Claim 1,
wherein the terminal support post (106) is configured to form a resistive tensile coupling with the portion of the guardrail W-beam (102) exiting the flattening portion (112),
wherein the terminal support post (106) comprises:a structural member having a longitudinal axis, the structural member for installing below grade adjacent the roadway,a connector assembly coupling the terminal portion of the guardrail beam (102) to the structural member (802) at an acute angle relative to the longitudinal axis of the structural member (802), the connector assembly comprising an opening through which the upstream end of the terminal portion of the guardrail beam (102) is disposed;wherein the coupling of the structural member and the terminal portion of the guardrail beam is maintained during an end-on or re-directive impact by a vehicle and is released during a reverse-direction impact,
wherein the connector assembly comprises a plurality of plates stacked adjacent to one another and disposed at an acute angle relative to the longitudinal axis of the structural member, at least one of the plurality of plates being affixed to an end of the structural member, the plurality of plates comprising:a first plate (810) comprising a rectangular plate with a V-shaped cut-out in an upper edge of the rectangular plate;a second plate (816) comprising a rectangular plate with a circular shaped opening; anda third plate (824) comprising a rectangular plate with a U-shaped cut-out in an upper edge of the third plate; andwherein the V-shaped cut-out, the circular opening, and the U-shaped cut-out are aligned with one another when the first, second, and third plates (810, 816, 824) are stacked adjacent to one another. - The end treatment (110) of Claim 1 or Claim 4, wherein the terminal portion of the guardrail W-beam (102) is substantially parallel to a roadway, or wherein the terminal portion of the guardrail W-beam (102) is flared away from a roadway at an upstream end of the guardrail W-beam (102).
- The end treatment (110) of Claim 5, wherein the flare is substantially parabolic, or wherein the flare is substantially linear.
- The end treatment (110) of Claim 1, wherein the terminal portion of the guardrail W-beam (102) comprises a longitudinally corrugated W-beam having upper and lower peaks and a valley between the peaks; and optionally wherein the terminal portion of the guardrail W-beam (102) is modified to include a slotted zone (202), the slotted zone (202) comprising a set of three slots extending longitudinally in each of the upper and lower peaks and the valley between the peaks, the slotted zone (202) increasing the ability of the terminal portion of the guardrail W-beam (102) to be flattened during the end-on impact; and optionally wherein flattening the guardrail W-beam (102) vertically comprises flattening the guardrail W-beam (102) into four vertically stacked plates.
- The end treatment (110) of Claim 1, further comprising a plurality of support posts (104) installed adjacent a roadway in spaced apart relation to one another, the plurality of support posts (104) coupled to the guardrail W-beam (102).
- The end treatment (110) of Claim 4, wherein the guardrail W-beam (102) comprises a longitudinally corrugated W-beam having upper and lower peaks and a valley between the peaks; and optionally wherein the terminal portion of the guardrail W-beam (102) is modified to include a slotted zone (202), the slotted zone (202) comprising a set of three slots extending longitudinally in each of the upper and lower peaks and the valley between the peaks, the slotted zone (202) increasing the ability of the terminal portion of the guardrail W-beam (102) to be flattened; and optionally wherein the upstream end of the guardrail W-beam (102) is flattened into four vertically stacked plates.
- The end treatment (110) of Claim 4, wherein the upstream end of the guardrail W-beam (102) is coupled to a threaded rod (1010), the threaded rod (1010) cooperating with the resistive, tensile coupling to maintain tension in the terminal portion of the guardrail W-beam (102) upon the end-on or re-directive impact by the vehicle.
- The end treatment (110) of Claim 4, further comprising a plurality of support posts installed adjacent a roadway in spaced apart relation to one another, the plurality of support posts coupled to the terminal portion of the guardrail W-beam.
- The end treatment (110) of Claim 11, further comprising an impact head (114) coupled to a first support post (104) disposed downstream from the terminal support post (106), the impact head (114) operable to be horizontally displaced in the downstream direction during an end-on collision for the dissipation of impact energy; and/or
the end treatment (110) of Claim 11, wherein at least one of the plurality of support posts (104) comprise a modified support post, the modified support post comprising:a lower portion (512) for installing below grade adjacent the roadway;a mid portion (514) that lies substantially adjacent the grade, the mid portion (514) including a weakened section operable to weaken the support post (104) about a first axis without substantially changing the behavior of the support post (104) about a second axis that is generally perpendicular to the first axis; andan upper portion (510) releasably coupled to the terminal portion of the guardrail W-beam (102).
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PL09743469T PL2313560T3 (en) | 2008-05-05 | 2009-05-05 | Guardrail safety system for dissipating energy to decelerate the impacting vehicle |
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US12/115,194 US7883075B2 (en) | 2008-05-05 | 2008-05-05 | Tension guardrail terminal |
US12/115,213 US7694941B2 (en) | 2008-05-05 | 2008-05-05 | Guardrail safety system for dissipating energy to decelerate the impacting vehicle |
PCT/US2009/042850 WO2009137483A1 (en) | 2008-05-05 | 2009-05-05 | Guardrail safety system for dissipating energy to decelerate the impacting vehicle |
Publications (2)
Publication Number | Publication Date |
---|---|
EP2313560A1 EP2313560A1 (en) | 2011-04-27 |
EP2313560B1 true EP2313560B1 (en) | 2017-11-22 |
Family
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Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP09743469.0A Active EP2313560B1 (en) | 2008-05-05 | 2009-05-05 | Guardrail safety system for dissipating energy to decelerate the impacting vehicle |
Country Status (15)
Country | Link |
---|---|
EP (1) | EP2313560B1 (en) |
KR (1) | KR20110004896A (en) |
CN (2) | CN103526705B (en) |
AU (1) | AU2009244438C1 (en) |
CA (2) | CA2725225C (en) |
CL (1) | CL2009001078A1 (en) |
DK (1) | DK2313560T3 (en) |
HK (1) | HK1191073A1 (en) |
IL (2) | IL209183A (en) |
MX (3) | MX361970B (en) |
NO (1) | NO2313560T3 (en) |
NZ (1) | NZ589467A (en) |
PL (1) | PL2313560T3 (en) |
WO (1) | WO2009137483A1 (en) |
ZA (1) | ZA201008503B (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11466415B2 (en) | 2018-12-07 | 2022-10-11 | Dean L. Sicking | Guardrail terminal |
Families Citing this family (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2010139027A1 (en) * | 2009-06-05 | 2010-12-09 | Saferoads Pty Ltd | An end terminal member |
WO2012106301A1 (en) | 2011-02-01 | 2012-08-09 | Energy Absorption Systems, Inc. | End terminal |
CN106988248B (en) * | 2017-05-17 | 2022-12-13 | 西北师范大学 | Intelligent isolation device for forming tidal lane and using method |
KR102007769B1 (en) * | 2017-09-01 | 2019-08-06 | 한국도로공사 | Reinforcing unit for transition section of roadway |
KR101898720B1 (en) * | 2017-11-24 | 2018-09-13 | 공주대학교 산학협력단 | Fixing block with expedite installation pile cap |
CN110159051B (en) * | 2019-04-29 | 2024-05-14 | 国网甘肃省电力公司建设分公司 | Power transformation framework |
CN110106811B (en) * | 2019-05-13 | 2021-06-01 | 四川轻化工大学 | Stress self-supporting protective guard for road steep slope |
CN115404804B (en) * | 2022-09-02 | 2023-10-03 | 湖南金宝涟交通设施工程股份有限公司 | Impact guiding type high-speed guardrail |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0924347B1 (en) * | 1997-12-22 | 2004-02-25 | Autostrada del Brennero S.p.A. | Safety barrier terminal for motorway guard-rail |
SE513130C2 (en) * | 1998-11-27 | 2000-07-10 | Anders Welandsson | Method and apparatus for preventing damage when colliding with the end portion of a road rail |
CN1135282C (en) * | 1999-07-21 | 2004-01-21 | 能量吸收系统公司 | Guardrail with sliding colliding absorbing element |
US8517349B1 (en) * | 2000-10-05 | 2013-08-27 | The Texas A&M University System | Guardrail terminals |
US7185882B2 (en) * | 2001-07-20 | 2007-03-06 | The Texas A&M University System | Box beam terminals |
NZ534325A (en) * | 2002-01-30 | 2006-03-31 | Texas A & M Univ Sys | Cable guardrail release system |
CN201024393Y (en) * | 2006-12-11 | 2008-02-20 | 北京中路安交通科技有限公司 | High speed highway steel pipe prestressed cable type crashproof movable guard bar |
CN101122120A (en) * | 2007-09-24 | 2008-02-13 | 曲涛 | Highway steel plate guardrail end decomposable shield protecting device |
-
2009
- 2009-05-05 NO NO09743469A patent/NO2313560T3/no unknown
- 2009-05-05 DK DK09743469.0T patent/DK2313560T3/en active
- 2009-05-05 EP EP09743469.0A patent/EP2313560B1/en active Active
- 2009-05-05 MX MX2016003949A patent/MX361970B/en unknown
- 2009-05-05 CL CL2009001078A patent/CL2009001078A1/en unknown
- 2009-05-05 CN CN201310322992.5A patent/CN103526705B/en not_active Expired - Fee Related
- 2009-05-05 AU AU2009244438A patent/AU2009244438C1/en active Active
- 2009-05-05 NZ NZ589467A patent/NZ589467A/en unknown
- 2009-05-05 CA CA2725225A patent/CA2725225C/en active Active
- 2009-05-05 KR KR1020107027209A patent/KR20110004896A/en not_active Application Discontinuation
- 2009-05-05 MX MX2010012170A patent/MX2010012170A/en active IP Right Grant
- 2009-05-05 CN CN2009801261792A patent/CN102084065B/en not_active Expired - Fee Related
- 2009-05-05 MX MX2013011074A patent/MX339695B/en unknown
- 2009-05-05 PL PL09743469T patent/PL2313560T3/en unknown
- 2009-05-05 WO PCT/US2009/042850 patent/WO2009137483A1/en active Application Filing
- 2009-05-05 CA CA2940944A patent/CA2940944C/en active Active
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2010
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2014
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Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11466415B2 (en) | 2018-12-07 | 2022-10-11 | Dean L. Sicking | Guardrail terminal |
US11846077B2 (en) | 2018-12-07 | 2023-12-19 | Sicking Safety Systems Llc | Guardrail terminal |
Also Published As
Publication number | Publication date |
---|---|
HK1191073A1 (en) | 2014-07-18 |
CN103526705B (en) | 2016-01-06 |
MX339695B (en) | 2016-06-06 |
NZ589467A (en) | 2013-03-28 |
EP2313560A1 (en) | 2011-04-27 |
PL2313560T3 (en) | 2018-04-30 |
CA2725225C (en) | 2016-11-01 |
CN102084065B (en) | 2013-08-28 |
WO2009137483A1 (en) | 2009-11-12 |
AU2009244438C1 (en) | 2020-10-22 |
IL209183A (en) | 2014-05-28 |
NO2313560T3 (en) | 2018-04-21 |
IL231529A0 (en) | 2014-04-30 |
IL231529A (en) | 2014-11-30 |
DK2313560T3 (en) | 2018-01-29 |
CA2940944A1 (en) | 2009-11-12 |
CN103526705A (en) | 2014-01-22 |
CA2940944C (en) | 2017-10-03 |
CL2009001078A1 (en) | 2010-04-16 |
MX2010012170A (en) | 2011-02-18 |
AU2009244438A1 (en) | 2009-11-12 |
IL209183A0 (en) | 2011-01-31 |
AU2009244438B2 (en) | 2015-08-27 |
CN102084065A (en) | 2011-06-01 |
AU2015249112A1 (en) | 2015-11-12 |
MX361970B (en) | 2018-12-19 |
CA2725225A1 (en) | 2009-11-12 |
ZA201008503B (en) | 2012-01-25 |
KR20110004896A (en) | 2011-01-14 |
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