CA1291355C - Highway barrier - Google Patents

Highway barrier

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Publication number
CA1291355C
CA1291355C CA000535996A CA535996A CA1291355C CA 1291355 C CA1291355 C CA 1291355C CA 000535996 A CA000535996 A CA 000535996A CA 535996 A CA535996 A CA 535996A CA 1291355 C CA1291355 C CA 1291355C
Authority
CA
Canada
Prior art keywords
panels
roadway
band
roadside
roadside structure
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
CA000535996A
Other languages
French (fr)
Inventor
Owen S. Denman
William S. Krage
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Energy Absorption Systems Inc
Original Assignee
Energy Absorption Systems Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Energy Absorption Systems Inc filed Critical Energy Absorption Systems Inc
Application granted granted Critical
Publication of CA1291355C publication Critical patent/CA1291355C/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • EFIXED CONSTRUCTIONS
    • E01CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
    • E01FADDITIONAL WORK, SUCH AS EQUIPPING ROADS OR THE CONSTRUCTION OF PLATFORMS, HELICOPTER LANDING STAGES, SIGNS, SNOW FENCES, OR THE LIKE
    • E01F15/00Safety 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
    • E01F15/14Safety 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
    • E01F15/143Protecting devices located at the ends of barriers

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  • Engineering & Computer Science (AREA)
  • Architecture (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Refuge Islands, Traffic Blockers, Or Guard Fence (AREA)

Abstract

ABSTRACT OF THE DISCLOSURE

A highway barrier includes a collapsible guard-rail assembly and a rotatable beam which is mounted between the rearward end of the guardrail assembly and a roadside hazard. The collapsible guardrail assembly includes a plurality of overlapping panels, adjacent ones of which are secured together by fasteners riding in slots. The fasteners are designed to retain the panels together after the impact and the fasteners are positioned with respect to the panels to cause the panels to tend to rotate away from the roadside during the impact, thereby redirecting the vehicle away from the roadway. The beam is rotatably mounted to the roadside hazard by a band and the forward end of the beam as well as the forward end of each of the panels is support-ed above the ground on a respective slip base designed to release in response to axial forces and to resist lateral forces. When an impacting vehicle engages the beam, the beam rotates away from the roadway around the roadside hazard, thereby redirecting the vehicle away from the hazard.

Description

3~

HIGHWAY BARRIER

BACKGROU~ OF THE INVENTION
... . _ The invention relates generally to systems for absorbing and dissipating the impact energy of auto-mobiles or other moving vehicles. More particularly, the invention relates to an improved highway barrier which will redirect the nose of an impacting vehicle away from a roadside hazard while at the same time dis-sipating kinetic energy of the impacting vehicle.
Rigid guardrails are usually positioned along side vehicular traffic routes, especially highways, to prevent vehicles from colliding with ~ixed objects, other vehicles or from leaving the road. To this end, the guardrails must be rigid enough to prevent the later-al movement of an impacting vehicle. While guardrails function to prevent vehicles from impacting unyielding objects, they themselves may present a hazard to a vehi-cle impacting the end portion of the unyielding guardrail.
Energy attenuation and absorbing devices for highway abutments are known in the art. An example of such a unit is United States Patent No. 4,352,484 to :

Gertz, et al. These dev.ices are utilized to ~.is~ipate the impact energy of a vehicle. To this end, thes~
barriers usually include a deformable structure or ma-terial which dissipates the energy of an impacting vehicle as it is crushed. Despite the success of ~hese devices they are typically too expensive to be u~ed to prevent vehicles from impacting guardrails.
Highway barriers have been developed for use with the end portions of guardrails. An example of these prior art devices are fender panels which are designed to telescope upon the application of an axial impact force. These prior guardrail barriers typically have difficulties dissipating the energy of large vehi-cles or vehicles traveling at high speeds. When these devices are impacted at high speeds, the fastening mem-bers are sometimes pulled through the panels causing the panels to separate and failing to telescope. Fur-thermore, if the telescoping panels do not dissipate a sufficient amount of the energy the impacting vehicle will hit the unyielding portion of the guardrail after the panels have telescoped. This can result in the fender panels of the guardrail spearing the car and seriously injuring its occupants.
Breakaway cable terminals are also used to dissipate the energy of a vehicle impacting the end portion of a guardrail. Basically, a breakaway cable terminal is a cable which extends from the first verti-cal support leg to a fender panel at a position in front of the second vertical support leg. Upon impact, the first vertical leg is designed to breakaway, thereby releasing the cable and minimizing the spearing forces.
This design has had difficulty in preventing light weight vehicles travelling at high speeds from being speared by a fender panel upon axial impact with the ~uardrail.

~3~:~55 SUMMARY OF THE INVENTION
The present invention is directed to an im-proved highway barrier which redirects an impacting vehicle away from a roadside hazard.
According to this invention, a highway bar-rier is provided for protecting an impacting vehicle from colliding with a roadside structure positioned alongside a roadway. This barrier comprises a beam having a forward and a rearward end. The rearward end of the beam is rotatably mountecl to the roadside struc-ture such that the beam is rotatable away from the roadway. A collapsible guardrail assembly is mounted to the forward end of the beam. This assembly includes a plurality of panels and means for mounting the panels together such that the panels extend alongside the road~
way and adjacent panels are slidable with respect to one another to allow the panels to telescope together when struck by the impacting vehicle. The panels are supported by means which allow the panels to telescope together when struck by the vehicle. The guardrail assembly is effective to deflect the impacting vehicle away from the roadway as the yuardrail assembly tele-scopes together when struck by the impacting vehicle.
The beam is effective to deflect the impacting vehicle farther away from the roadway and the roadside struc-ture as the beam rotates with respect to the roadside structure.
In the past, beams have been rotatably mount-ed to a roadside structure so as to redirect an impac-ting vehicle away from the structure. However, when asimple rigid beam is used without the collapsible guard-rail assembly described above, there is a tendency for the beam to fail to rotate when the vehicle is approach ing the beam axially. When this happens, the beam ~91~35S

provides a rigid barrier which can do considerable dam-age to the vehicle and can injure the occupants of the vehicle. It has been discovered that the collapsible guardrail assembly described above cooperates with the rotatable beam to reduce the likelihood that the beam will spear the impacting vehicl.e. In particular, the collapsible guardrail assembly deflects the impacting vehicle away from the roadway as it telescopes togeth-er. In many cases, the impacting vehicle is deflected sufficiently by the collapsing guardrail assembly such that the vehicle either misses the rotatable b~arn en-tirely or strikes the rotatable beam at a sufficient angle to cause the beam to begin to rotate, thereby deflecting the impacting vehicle farther away from the roadway. Thus, the guardrail assembly cooperates with the rotatable beam to provide a markedly improved high-way barrier.
The invention itself, together with further objects and attendant advantages, will best be under-stood by reference to the fol.lowing detailed descrip-tion, taken in conjunction with the accompanying draw-ings.

3RIEF D~SCRIPTION OF THE DRAWINGS
.. _ Figure 1 is a plan view of a first preferred embodiment of a guardrail end terminal.
Figure la is a side elevation view of a sand saddle utilized in the guardrail end terminal of Figure 1.
Figure 2 is a side elevation view of the guardrail end terminal of Figure l.
Figure 3 is a cross-sectional view taken along line 3-3 of Figure 2.
Figure 4 is a side elevation view of a por tion of the guardrail end terminal of Figure 1.

~ X~ 3S~

Figure 5 is a cross-sectional view taken along line 5-5 of Figure 4.
Figure 6 is a cross-sectional view taken along line 6-6 of Figure 4.
Eigure 7 is a side ele~ational view in partial cutaway of a slip base included in the guardrail end terminal of Figure 1.
Figures 8a-8f are a series of schematic plan views which illustrate the lateral pole vaultiny effect of the guardrail end terminal of Figure 1.
Figure 9 is a side elevation of a highway barrier which incorporates a second preferred embodi-ment of this invention.
Figure 10 is a plan in partial section taken along line 10-10 of Figure 9.
Figures lla-llf are six consecutive plan views showing the operation of the embodiment of Figures 9 and 10 when struck by an impacting vehicle.
Figures 12a and 12b are consecutive plan views showing a second mode of operation of the embodiment of Figures 9 and lO when struck by an impacting vehicle.
-~` Figure 13 is a partial side elevation of a highway barrier which lncorporates a third preferred embodiment of this invention.
Figure 14 is a plan in partial section taken along lines 14-14 of Figure 13.
Figure 15 is a plan corresponding to Figure 14 showing the beam in a rotated position after impact by a vehicle.

DETAILED DESCRIPTION OF T~E PREFERRED EMBODIMENTS

The First Preferred Embodiment The first preferred embodiment is shown in FIGS. 1-8f, and it include a plurallty of nested a3~ SS

fender panels which telescope in response to an axial impact force and a cable for urging a first fender panel laterally upon the application of the axial impact force. The fender panels and cable function to direct the nose of the impacting vehicle away from a hard point on the guardrail while at the same time dis-sipating the impact energy of the vehicle.
The fender panels of this first embodiment are slotted and secured together in a nested fashion by fasteners which allow the fender panels to telescope upon the application of an axial impact force. The fender panels are supported above the ground on verti-cal support legs which are positioned on slip bases whi~h allow the legs to break away from ground anchors so that the fender panels may telescope.
The first fender panel of this first embodi-ment and more specifically its vertical support leg is connected to a cable which is anchored to a front cable anchor located in front of the fender panels and a rear cable anchor located perpendicular to the guardrail.
The cable is positioned so that when an axial impact force starts the first panel telescoping the cable will urge the fender panel laterally. This will cause a "lateral pole vaulting effect" which will urge the vehi-cle away from the hard point on the guardrail.
This first preferred embodiment provides impor-tant advantages in that it both dissipates kinetic energy of the impacting vehicle and redirects the vehicle away from the hard point. Thus the vehicle is both slowed and shifted laterally, and in many cases the vehicle is prevented from colliding with the hardpoint even though the vehicle is not brought to a rest before the hard point.
Turning now to the drawings, Figure 1 illus-trates a plan view of the first preferred embodiment of 1~3~355i the guardrail end terminal lO. The guardrail end ter-minal 10 is attached to and acts as the end portion of a guardrail 12. The guardrail end terminal 10 is de-signed to prevent vehicles from impacting head on the hard point 14 of the guardrail 12. The hard point 14 of the guardrail 12 is that portion of the guardrail which is not designed to yield upon impact with a vehi-cle. As will be described in greater detail below, the guardrail end terminal 10 is designed to redirect the front end of an impacting vehicle away from the hard point 1~ while at the same time dissipating the eneryy of the impact force of the vehicle.
Referring now to Figures 2 and 4, the guard-rail end terminal 10 includes a plurality of nested fender panel~ 18. The fender panels 18 include slots 20 and are secured together by a plurality of fastener members 22 which allow the fender panels to telescope upon the application of an axial impact force.
The fastener members 22 are designed to en-gage the slot 20 of one of the fender panels 18 and anaperture 21 of a second fender panel 18. By way of example, Figure 3 illustrates the attachment of two fender panels 18a and 18b by a fastener member 22. The fastener member 22 includes a plate member 23 and a bolt 26. The plate member 23 has a preferably rectan-gular shape which conforms to the surface of the fender panel 18a, and thereby includes curved ends 31 and 33.
The plate member 23 further includes a funnel shaped aperture 27 which leads to a neck portion 29. The aper-ture 27 and neck portion 29 are designed to receive abolt 26. To this end, the bolt 26 includes a head 30 which conforms to the shape of the aperture 27 of the plate member 23.
The plate member 23, and more specifically the neck portion 29, is designed to be received within ~;~'31355 a slot 20 in a first fender panel 18a and rest on the shoulders 62 which surround an aperture 21 in the sec-ond fender panel 18b. Once so received, the plate member 23 is secured on a side of the fender panel 18a by the bolt 26 which is received within the aperture 27 and then secured in place by a washer 64 and nut 88.
The fastener member 22 is constructed so that it does not clamp the two fender panels 18a and 18b together but rather secures them in juxtaposition to one another with a sufficient tolerance to allow the first fender panel 18a to telescope into the second fender panel 18b. Because of the construction of the fastener member 22 and specifically the plate member 23, when a sufficient axial impact force is applied to the first fender panel 18a the fastener member 22 will ride in slot 20 allowing the panel 18a to move axiall~
with respect to the second fender panel 18b in a tele-scoping fashion. The axial movement of the first fender panel 18a will only be impeded upon the end of the slot 20 reaching the fastener member 22.
The funnel shape of the aperture 27 in the plate member 23 and shape of the head 30 of the bolt 26 prevent the bolt 26 from being pulled through the slot 20 when the fender panels 18 are telescoping in re-sponse to an axial impact force. Thus, when an axialimpact force is applied to the fender panels 18 the fastener members 22 allow the panels to telescope along the slots 20.
The fender panels 18 are supported above the ground 42 by vertical support legs 28. Preferably, the support legs 28 are steel I Beams. In the preferred embodiment illustrated in the drawings, the vertical support legs 28 are bolted to a blockout 30 which is bolted to the fender panels 18. The blockouts 30 pre-vent automobiles with small wheels from snagging on the verti.cal support legs 28 when they impact the guardrail end terminal 10 at a glancing angle. The blockouts 30 are also preferably steel "I Beams."
As shown in Figures 4 and 5, the vertical support legs 28 are secured to a slip base 30. The slip base 30 includes a top plate 32 and a bottom plate 34 which are secured to each other. The bottom plate 34 is fastened, as for example by welding or bolting, to a ground anchor 70. Various types of ground anchor constructions 70 are known in the art. By way of example, the ground anchor 70 may include a steel rect-angular tubing 72 which is plugged into a concrete foot-ing 74 to securely position it in the ground 42. The top plate 32 is welded to the vertical support leg 28.
Referring now to Figures 5 and 7, the top and bottom plates 32 and 34 each include four slots 36, each slot being designed to receive a bolt 38 which secures the plates 32 and 34 together. The plates 32 and 34 are large enough so that they will not yield upon a lateral impact force. The slots 36 are open ended so that when a sufficient axial impact force is applied to the vertical support leg 28 the plates 32 and 34 will slide apart, as illustrated in Figure 7.
To insure that the plates 32 and 34 will slip apart the plates 32 and 34 are separated by four washers 39. The washers 39 define the area at which the plates 32 and 34 are joined so that the force needed to cause the plates 32 and 34 to slide apart can be controlled. It has been found that if the plates 32 and 34 are boltad together at 60 foot-pounds (8.28 Kg-m) sufficient ener-gy will be dissipated by the slip bases.
~s shown in Figure 5, the vertical support legs 28 may include an angle plate 68. The angle plate 68 is attached to the front of the top plate 32 and helps to prevent the support legs 28 from becoming hung ;355 up on each other as they breakaway in response to an axial impact force. Because there is no vertical sup-port leg 28 to collapse into it, the first vertical support leg 28a does not include an anyle plate 68.
Referring now to Figures 1, 4 and 6, the first vertical support leg 28a is of substantially the same construction as the other vertical support legs 28 except that it contains an aperture 40. The aperture 40 is located in the lower portion of the leg 28a and is designed to receive a cable 48. As shown in Fiyure 2, the ~able 48 extends from a front cable anchor 46 through the aperture 40 in the first vertical support ley 28a to a rear cable anchor 50. As will be described in detail below, the cable 48 urges the first fender panel 18a laterally upon the application of an axial impact force.
The rear cable anchor 50 is located perpen-dicular to the guardrail 12 and includes an earth anchor 56 and rod 58. Preferably, the ground anchor 56 is a typical concrete anchor. The rod 58 is secured within the ground anchor 56 and is designed to secure an end of the cable 48. The front cable anchor 46 is located in front of the first vertical support leg 28a and also includes a ground anchor which secures the front end of the cable 48. The cable 48 is passed through the aper ture 40 in the first vertical support leg 28a and then secured to the front and rear cable anchors 46 and 50.
Thus, the cable 48 extends from the front cable anchor 46 through the first vertical support leg 28a to the rear cable anchor 50. Because the rear cable anchor 50 is located perpendicular to guardrail 12 the cable 48 extends from the front first vertical support leg 28a at an acute angle to the guardrail end terminal lO. As shown in Figure 6, to insure that the cable 48 extends from the first vertical support leg 28a at the ~;~'3~L3~

proper angle and to prevent the cable from wearing through on the leg 28a a sleeve 59 extends from the aperture 40 on each of its sides and receives the cable 48. The sleeve 59 also helps to dissipate the energy of an impacting vehicle by being dragged down the cable 48 during impact and thereby exerting a deacceleration force.
The cable 48 provides redirectioning to a vehicle which impacts the guardrail end terminal 10 head on. To this end, the cable 48 is designed to urge the first fender panel 18a la~erally upon application of an axial impact force. By urging the first fender panel 18a laterally, the cable 48 causes, as will be described in more detail below, a "lateral pole vault-ing effect" on the panels 18. The cable 48 is preferably constructed from steel and is sized such that it will stretch to about 1 to 1-1/2% its length upon applica tion of an impact force. By experimentation it has been found that a steel cable 48 with a diameter of 7/8 of an inch (2.2225 cm) is sufficient to urge the panels 18 laterally.
Referring now to Figures 8a-8f, the lateral pole vaulting effect of the guardrail end terminal 10 is illustrated. When a vehicle impacts the guardrail end terminal 10 head on, the first panel 18a is forced backwards telescoping into the second panel 18b. To this end, the first panel 18a slides axially along the fastening member 22. As the vehicle continues its mo-tion, it impacts a second vertical support leg 28a causing the top plate 32 of the second slip base 30 to slip away from the bottom plate 34.
The rearward movement of the first panel stretches the cable 48 until the cable will not stretch any further (approximately 1 to 1-1/2% of its length).
The cable 48 then urges the first panel 18a laterally 3S~.

causing -the first fender panel 18a to give a small lateral impulse to the nose of the impacting vehicle.
As the first fender panel 18a reaches the end of its travel the second fender panel 18b begins to telescope i.nto the third fender panel 18c. The first fender panel 18a will reach the end of its axial movement be-fore the second slip base 30b can break free. Each slip base 30 dissipates some of the energy of the impacting vehicle. This process continues until all the fender panels 18 of the guardrail end terminal 10 have broken free giving a large lateral force to the impacting vehicle causing it to be directed away from the hard point 14.
Because the slip bases 30 may not remove a sufficient amount of energy to keep an impacting vehi-cle from hitting the hard point 14, the guardrail end terminal 10 may include sand saddles 60. The sand saddles 60 are containers which are filled with a de-sired amount of sand 78. As illustrated in Figure la, each sand saddles 60 includes two containers 74 and 76.
Each container 74 and 76 includes a bolt 72 which allows the two containers to be attached to each other to form the sand saddle 60. The containers 74 and 76 have a construction that conforms to the blockouts 30 and I
Beams 28. The sand saddle 60 also includes a lid 70 which snaps over the two containers 74 and 76.
It has been found that by adding about 200-300 pounds (90-135 Kg~ of sand to the sand saddles 60, the energy of most impacting vehicles i~ sufficiently reduced, through momentum transfer to the sand, to allow the guardrail end terminal 10 to redirect the impacting vehicle and thereby prevent the vehicle from impacting the hard point 14. Preferably, the first two sand saddles 60 are filled with 200 pounds (90 Kg) of 1~9~L3~S
-13~

sand and the third sand saddle is filled with 300 pounds (135 Kg) of sand.
By adjusting the angle at which the cable 48 extends away from the first fender panel 18a, the mass of the vehicle that can be redirected can be increased.
But, it should be noted that the greater the angle of the cable 48, the more unyielding the guardrail end terminal 10 will be. It has been found that an angle of approximately 25 redirects most road vehicles away from the hardpoint 14 of the yuardrail 12 while at the same time providing a guardrail end terminal 10 which is sufficiently yielding to protect the occupants of most impacting vehicles.
The first fender panel 18a may include a bull nose 57. The bull nose 57 provides a curved area for an impacting vehicle to hit instead of a pointed fender panel 18.
Referring now to Figures 1 and 2, the guard-rail end terminal 10 may be used with a standard anchor cable system. The standard anchor cable system includes a second cable 82 which extends from the ground anchor 46 of a vertical support leg 28 to a transition fender panel 84 in the guardrail 12. The transition fender panel 84 is connected to the last fender panel 18e of the guardrail end terminal 10 and the hard point 14 of the guardrail 12. The second cable 82 is received within a rectangular block 86 which is attached to the transition fender panel 84.

The Second And Third Preferred Embodiments The second and third preferred embodiments of Figures 10-15 both include a collapsible guardrail assem-bly, substantially identical to that described above in conjunction with Figures 1-8, in combination with a beam which is rotatably mounted to a roadside hazard.

~X~3;~ 5.5 Turning now to Fiyures 9-12b, the second preferred embodiment includes a highway barrier 100 which is mounted alongside of and generally parallel to a roadway as shown in Figure 10. The highway barrier 100 is provided to protect vehicles which leave the roadway from colliding with a roadside hazard such as a pole 102.
The barrier 100 includes a beam assembly 110 which is rotatably mounted to the pole 102. This beam assembly 110 includes a rigid beam 112 which may, for example, be a Thrie beam of the type described above in conjunction with the first embodiment. A steel band 114 is mounted around the pole 102 to encircle the pole 102, and the rearward end of khe beam 112 is fastened securely to the band 114 by fasteners 116. A riyid brace 118 is provided which includes a forward flange 120 that is rigidly bolted to the beam 112 by fasteners 124 as well as a rearward flange 122 which is rigidly secured to the band 114, as for example by welding. A
collar 126 is rigidly secured to the pole 102, and the collar 126 supports the band 114 in vertical position, without interfering with the freedom of the band 114 to rotate about the pole 102. A tubular spacer 128 is mounted withln the band 114 between the pole 102 and the brace 113. The spacer 128 is sized to be more readily deformed than the pole 102 such that the spacer 128 will deform before the pole 102 during the impact of a vehicle. The band 114 can be formed for example of steel of 1/4 to 3/4 inch thickness and should preferably be strong enough to ensure that the beam 112 remains rotatably mounted to the hazard 102 during normal operation of the highway barrier 100. The spacer 128 is typically formed of steel tubing of 1/8 to l/2 inch in wall thicknass.

1~3~ S

The barrier 100 also includes a collapsible guardrail assembly 140. This yuardrail assembly 140 is quite similar to that described above in conjunction with the first preferred embodiment and includes an array of axially extending overlapping panels 142.
Each of the panels 142 defines an axially extending slot 144 positioned between the respective forward end 146 and rearward end 148 of the panel 142. Fasteners 150 of the type shown above in Figure 3 extend between the forward end 146 of the lnner of each pair of over-lapping paneLs 142 and the slot 144 of the outer of each pair of overlapping panels 142. In this embodi-ment, the fasteners 150 pass through openings in the forward ends 146 of the panels 142, and these openings are preferably positioned within six inches of the extreme forward edge of the panels 142. Preferably, the fasteners 150 are each positioned forwardly of the adjacent blockout 160.
The panels 142 are supported above the yround on ground supports 152 which in this embodiment take the form of separate concrete foundations. Of course, a single concrete slab or other suitable foundation may be substituted in alternate embodiments. The ground supports 152 support vertical panel supports 154, which in this embodiment take the form of I Beams as described above in conjunction with the first preferred embodi-ment. Each of the panel supports 154 is secured to the respective ground support 152 by a respective slip base 156 of the type described above in conjunction with Figure 7. In each case, four fasteners 158 are includ-ed in the slip base 156 to secure the ground support 152 to the panel support 154. The slip bases 156 are arranged to resist lateral forces exerted transverse to the longitudinal extent of the guardrail assembly 140, while allowing the panel supports 154 to move axially, ~ ~91;3~;

off of the ground supports 152, in response to axial forces applied by an impacting vehicle. Generally, the rearward slip base 156 which supports the forward end of the beam 112 is fastened together more tightly than the other slip bases 156 to cause it to release last.
In each case an I Beam blockout 160 is bolted between the respective panel support 154 and the for-ward end 146 of the respective panel 142. The block-outs 160 space the panels 142 laterally towards the roadway with respect to the pa~lel supports 154. The forward most end of the guardrail assembly 140 defines a curved nose piece 162. In this embodiment the curved nose piece 162 is formed of a plastic which cleforms easily to allow the impacting vehicle to engage the forward most end of the front fender panel 142. Also, one or more of the panel supports 154 may support a container 164, similar to that described above in conjunction with Figure la. These containers 164 are preferably adapted to contain between two and three hundred pounds of sand to increase the inertial mass of the guardrail assembly 140.
Turning now to Figures lla-lle, these figures illustrate one mode of operation of the barrier 100 when struck by an impacting vehicle 104. Preferably, the slip base 156 at the forward end of the rotatable beam 112 is tightened to a greater extent than the re-maining slip bases 156 so that it is the last to release.
In many applications, it is preferable to provide the two forward most slip bases 156 with flared openings to increase the angular range of impact directions that will cause the slip bases 156 to release.
Figure lla shows the barrier 100 in its orig-inal position with a vehicle 104 proceeding axially toward the pole 102. As shown in Figure llb, the first step in the collision is for the forward most slip base 5~:;

156 to release and the forward most panel 142a to slide rearwardly with respect to the remaining panels 142b-142e.
As shown in Figure llc, when the forward most panel 142a moves to the rear to the maximum extent permitted by the slot 144, the forward most panel 142a tends to rotate away from the roadway, thereby exerting a later-al force on the impacting vehicLe 104 which tends to move the vehicle 104 away from the roadway. This lateral force is a result of the "pole vaulting effect"
discussed above.
This action of the co:Llapsing guardrail assem-bly 140 is provided by the asymrnetrical structure of the telescoped panels 142. When the forward most panel 142a is fully telescoped, the rearward end 148 of the forward most panel 142a overlaps to a large extent with the second panel 142b. This overlap substantially pre-vents the forward most panel 142a from rotating towards the roadway. However, as explained above, the fastener 150 is secured to the extreme forward end 146 of the second panel 142b, which is relatively weak with regard to its ability to resist rotation of the forward most panel 142a away from the roadway. Because of the above described asymmetry with respect to forces required to bend the forward most panel 142a away from the roadway as compared with the forces re~uired to bend the for-ward most panel 142a towards the roadway, the forward most panel 142a tends to rotate away from the roadway during the impact (counterclockwise as shown in Figure llc), thereby pushing the impacting vehicle 104 away from the roadway as well.
Of course, once the forward most panal 142a has telescoped completely, the second panel 142b begins to move rearwardly and leaves its slip base 156. This process of consecutive telescoping continues as shown in Figure lld, with each of the panels 142 exerting a ~l~'3~SS

lateral force on the impacting vehicle 104 away from the roadway as the collapse of the guardrail assembly 140 continues.
In the event this proyressive collapse of the guardrail assembly 140 continues to the point where the vehicle 104 exerts significant compressive forces on the rotatable beam 112, such compressive forces on the beam 112 will cause the beam 1].2 to indent the spacer 128 against the pole 102, thereby releasing the slip base 156 of the beam 112. Once the slip base 156 is released, the beam 112 is free to rotate about the pole 102. The beam 112 is relatively rigid, and it exerts a large lateral force on the impacting vehicle 104 as it is rotated around the pole 102 by the vehicle 104.
This large lateral force moves the vehicle 104 farther away from the roadway, thereby diverting the vehicle 104 around the pole 102.
It should be understood that the beam 112 will not be caused to rotate with respect to the pole 102 in many cases. As shown in Figures 12a and 12b, in the event the vehicle 104 is positioned and oriented such that the collapsing guardrail assembly 140 moves the vehicle 104 sufficiently away from the roadside, the guardrail assembly 140 will buckle, allowing the vehicle 104 to move past the pole 102 without rotating the beam 112.
The preferred embodiment of Figures 9-12 is adapted for use with a cylindrlcal roadside ha~ard such as a utility pole, lamp pole, bridge pier, or the like.
Of course, if desired a cable similar to the cable 48 of Figure 1 may be used with the embodiment of Figures 9-12. The present invention can readily be adapted for use with other relatively narrow roadside hazards which are not cylindrical. Figures 13-15 illustrate one such embodiment.

., 1~913~S

This third preferred embodiment includes a roadside barrier 200 adapted to protect an impactiny vehicle from contact with a wall 202. This barrier 200 includes a beam assembly 210 which includes a riyid beam 212 similar to that described above in conjunction with Fiyure 9. A band 214 is provided which defines a first pair of slots 215 and a second pair of slots 217 positioned on opposite sides of the wall 202. Fasteners 219, 221 are used to secure the band 214 to the wall 202. The fasteners 219 pass through the slots 215 and are positioned near the forward ends of the slots 215 to allow the band 214 to move forwardly with respec~ to the fasteners 219. Conversely, the fasteners 221 pass through the slots 217 and are positioned near the rear-ward end of the slots 217. Thus, the slots 215, 217 are positioned so as to retard the beam 212 from rotat-ing towards the roadway and to facilitate rotation of the beam 212 away from the roadway.
A brace 218 is provided which includes a beam flange 220 that is mounted to the beam 212 by fasteners 224 and a band flange 222 that is welded to the band 214. The brace 218 operates similarly to the brace 118 described above. A spacer 228 is positioned between the wall 202 and the band 214. The barrier 200 also includes a guardrail assembly 240 identical to the guard-rail assembly 140 described above.
The embodiment of Figures 13-15 operates in a manner similar to that described above in conjunction with Figures lla 12b. In particular, the guardrail assembly 240 shifts the impacting vehicle 104 laterally away from the roadway as the guardrail assembly 240 collapses. In the event the impacting vehicle 104 en-gages the beam 212, the beam 212 is shifted rearwardly slightly, thereby partially collapsing the spacer 228.
This releases the beam 212 from its slip base and allows '31~55 the beam 212 to rotate. The fasteners 219, 221 cooper-ate with the slots 215, 217 to prevent the beam 212 from rotating towards the roadway while allowing the beam 212 to rotate away from the roadway. The momentum 5 of the impacting vehicle therefore causes the beam 212 to rotate as shown in Figure 15, away from the roadway.
This rotation applies large lat:eral forces to the vehi-cle, thereby redirecting the vehicle around the wall 202.
From the foregoing, it should be apparent that two embodiments of an improved highway barrier have been disclosed which provide importank advantages.
The asymmetrical folding of the collapsible guardrail assembly imposes lateral forces on the impacting vehi-15 cle, thereby redirecting the vehicle to some extent away from the roadway. In the event these guardrail forces are not sufficient to cause the impacting vehi-cle to miss the roadside hazard, the vehicle engages the rotatable beam and the beam supplies large lateral 20 forces which redirect the vehicle away from the hazard.
Because of the manner in which the panels fold when collapsed, they provide a relatively large buffer area against the forward portion of the impacting vehicle, thereby reducing maximum surface loading on the vehi-25 cle to reduce the possibility of the guardrail spearinginto the impacting vehicle.
Of course, it should be understood that a wide range of changes and modifications can be made to the preferred embodiments described above. For example, 30 the number of fenders used in any particular highway barrier can be increased or decreased as appropriate for the particular application. As pointed out above, various types of ground bases including continuous con-crete pads can be used. If desired, a planar keeper 35 plate can be interposed between the moveable parts of ~3i.3~

the slip base to retain the fasteners in position prior to assembly. It is therefore intended that the ~orego-iny detailed descriptlon be regarded as illustrative rather than limiting, and that it be understood that it is the following claims, including all equivalents, which are intended to define the scope of this invention.

Claims (15)

1. A highway barrier for protecting an impacting vehicle from colliding with a roadside structure positioned alongside a roadway, said barrier comprising:
a beam having a forward end and a rearward end;
means, coupled to the rearward end of the beam, to the roadside structure such that the beam is rotatable away from the roadway; and a collapsible guardrail assembly mounted to the forward end of the beam, said guardrail assembly comprising;
a plurality of panels;
means mounting the panels together such that the panels extend alongside the roadway and mounting adjacent panels slidable with respect to one another to allow the panels to telescope together when struck by the impacting vehicle; and means coupled to the panels and connectable to at least one roadside element for supporting the panels and allowing the panels to telescope together when struck by the impacting vehicle;
said panels and mounting means configured to deflect the impacting vehicle away from the roadway as the guardrail assembly telescopes together when struck by the impacting vehicle; and said beam effective to deflect the impacting vehicle farther away from the roadway and the roadside structure as the beam rotates with respect to the roadside structure.
2. The invention of Claim 1 wherein the means for mounting the panels together comprises:
means for defining a longitudinally extending slot in each of the panels; and means for interconnecting adjacent panels together, which interconnecting means comprises a plural-ity of fasteners, each extending through a respective one of the slots, said slots positioned such that the panels tend to collapse in a selected direction away from the roadway.
3. The invention of Claim 1 wherein the means for supporting the panels comprises:
a plurality of panel supports, each defining an upper end secured to a respective one of the panels and a lower end;
a plurality of support surfaces, each aligned with a respective one of the panel supports; and a plurality of slip bases, each interconnect-ed between a respective one of the panel supports and the respective support surface, each of said slip bases comprising means for preventing lateral movement of the panel support with respect to the support surface and means for permitting axial movement of the panel sup-port with respect to the support surface to allow the panels to telescope together when struck by the collid-ing vehicle.
4. The invention of Claim 1 wherein the means for rotatably mounting the rearward end of the beam to the roadside structure comprises:
a band which encircles the roadside struc-ture; and means for securing the band to the rearward end of the beam.
5. The invention of Claim 4 wherein the rotata-bly mounting means further comprises a collapsible cylinder interposed between the band and the roadside structure adjacent the securing means.
6. The invention of Claim 4 wherein the rotata-bly mounting means further comprises;
a collar secured to the roadside structure beneath the band to rotatably support the band in place.
7. The invention of Claim 1 wherein the means for rotatably mounting the rearward end of the beam to the roadside structure comprises;
a band;
first means for securing the rearward end of the beam to the band; and second means for rotatably securing the band to the roadside structure, said second means compris-ing:
means for defining a first slot in the band adjacent a first side of the roadway structure;
means for defining a second slot in the band adjacent a second side of the roadway structure, and first and second fasteners, each passing through a respective one of the slots and secured to the roadside structure;
said beam being rotatable with respect to the roadside structure as the slots slide with respect to the fasteners.
8. The invention of Claim 7 wherein the fasten-ers are positioned at selected ends of the slots to impede rotation of the beam toward the roadway and to permit rotation of the beam away from the roadway.
9. A highway barrier for protecting an impacting vehicle from colliding with a roadside structure posi-tioned alongside a roadway, said barrier comprising:
a band pivotably secured to the roadside structure;
a beam mounted to the band to extend axially alongside the roadway such that the beam is pivotable about the roadside structure;
a plurality of fender panels, each defining an axial slot, said fender panels extending generally axially in overlapping configuration;
a plurality of fasteners, each extending through a respective one of the slots and secured into a forward end of an adjacent rearward fender panel to allow the fender panels to telescope together in re-sponse to an axial force;
means for securing a rearward one of the fender panels to the beam;
a plurality of panel supports, each secured to the forward end of a respective one of the fender panels; and a plurality of slip bases, each secured be-tween a respective one of the panel supports and a support surface, said slip bases oriented to allow axial movement of the panel supports while preventing lateral movement of the panel supports;
said slots and fasteners positioned to cause the fender panels to move away from the roadway as the fender panels collapse following telescoping;

said beam and band effective to swing the impacting vehicle away from the roadway.
10. The invention of Claim 9 wherein the band encircles the roadside structure.
11. The invention of Claim 9 wherein the band defines a plurality of slots, and wherein the band is secured to the roadside structure by a plurality of fasteners, each passing through a respective one of the slots.
12. The invention of Claim 11 wherein the fasteners are positioned in the slots to resist pivoting of the beam toward the roadway and to facilitate pivoting of the beam away from the roadway.
13. The invention of Claim 9 further comprising a collapsible cylinder interposed between the band and the roadside structure on a side of the roadside structure facing the fender panel.
14. The invention of Claim 1 wherein the forward end of the collapsible guardrail assembly is connectable to roadside structure only by the supporting means.
15. The invention of claim 9 wherein all of the panel supports are connected only to roadside structure situated in general axial alignment with the beam and the fender panels.
CA000535996A 1986-05-01 1987-04-30 Highway barrier Expired - Fee Related CA1291355C (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US85859186A 1986-05-01 1986-05-01
US858,591 1986-05-01

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CA1291355C true CA1291355C (en) 1991-10-29

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CA000535996A Expired - Fee Related CA1291355C (en) 1986-05-01 1987-04-30 Highway barrier

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EP (1) EP0245042B1 (en)
JP (1) JPH07103539B2 (en)
AU (1) AU583726B2 (en)
CA (1) CA1291355C (en)
DE (1) DE3763895D1 (en)

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US4928928A (en) * 1988-01-12 1990-05-29 The Texas A&M University System Guardrail extruder terminal
US5078366A (en) * 1988-01-12 1992-01-07 Texas A&M University System Guardrail extruder terminal
US6220575B1 (en) 1995-01-18 2001-04-24 Trn Business Trust Anchor assembly for highway guardrail end terminal
NZ501309A (en) 1997-05-09 2001-12-21 Exodyne Technologies Inc Breakaway support post for highway guardrail end treatments
EP0924347B1 (en) * 1997-12-22 2004-02-25 Autostrada del Brennero S.p.A. Safety barrier terminal for motorway guard-rail
US6173943B1 (en) * 1998-04-22 2001-01-16 Energy Absorption Systems, Inc. Guardrail with slidable impact-receiving element
US6398192B1 (en) 1999-01-06 2002-06-04 Trn Business Trust Breakaway support post for highway guardrail end treatments
US6783116B2 (en) 1999-01-06 2004-08-31 Trn Business Trust Guardrail end terminal assembly having at least one angle strut
JP4282883B2 (en) * 2000-08-24 2009-06-24 日鐵住金建材株式会社 End shock absorber
CA2420729C (en) 2000-08-31 2008-12-09 The Texas A&M University System Et-plus: head assembly for guardrail extruder terminal
US8517349B1 (en) 2000-10-05 2013-08-27 The Texas A&M University System Guardrail terminals
KR101339447B1 (en) * 2013-04-18 2013-12-10 신도산업 주식회사 Guardrail end terminal
CN114737474A (en) * 2022-04-20 2022-07-12 叶洪波 Large-span assembly type steel bridge structure
CN115323961B (en) * 2022-07-11 2024-03-19 泉州装备制造研究所 Road safety guard rail

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Also Published As

Publication number Publication date
AU7226187A (en) 1987-11-05
EP0245042A1 (en) 1987-11-11
JPH07103539B2 (en) 1995-11-08
DE3763895D1 (en) 1990-08-30
AU583726B2 (en) 1989-05-04
JPS62268409A (en) 1987-11-21
EP0245042B1 (en) 1990-07-25

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