This disclosure relates to a dynamic translating pedestrian access terminal such as may be used in a roadside traffic barrier to permit pedestrian access to a beach front or other attraction.
As used herein, “attenuator” shall mean an energy absorbing material, structure or device.
A need has been identified along roadways adjacent to pedestrian attractions such as waterbodies and hiking trails where roadside barriers are required to protect errant vehicles from encroaching into the waterbody or trail while maintaining access points through the barrier system for residents living on the opposite side of the roadway to get to the beach, dock, or trail (which may be beyond the roadway right-of-way and owned by the resident).
In some instances, local road authorities create access points through the barrier system that compromise the performance capability of the system to redirect an errant vehicle. This creates potentially hazardous ends that could penetrate and spear vehicle occupants. In other situations, residents have cut or removed parts of the barrier to provide access points.
There is a need to provide standard crashworthy terminal systems on either side of an access point that will properly anchor the end of a road barrier, such as a W-beam or thrie-beam or cable barrier system, to make the roadside barrier system redirective and functional. There is a need to provide standard crashworthy terminal systems to eliminate the potential spearing hazard of a W-beam guardrail improperly terminated with a fish-tail.
Current standard crashworthy terminal systems have gating characteristics which means that when a vehicle impacts them near the start of the terminal, they gate out of the way. One disadvantage to these systems when placed on either side of a gap is that the effective length of the gap through which an errant vehicle could get through the system into the waterbody or other terrain hazard is much longer than the physical opening length of gap provided for pedestrian access.
Terminal systems for a W-beam guardrail are typically gating systems. Another disadvantage to these systems is that W-beam terminal systems typically gate during impacts in advance of the third post downstream of the impact head. Therefore, W-beam terminal systems with a W-beam guardrail on either side of a narrow 33 inch to 65 inch wide access point for pedestrians may result in an effective gap length of approximately 30 feet. For high tension cable barrier system terminals, the effective gap length is significantly longer.
Another disadvantage to these systems is that grading requirements behind gating terminal systems require widening of the roadway in advance and along the terminal and flatter traversable slopes perpendicular to the roadway for the systems to perform as designed. At many roadway locations adjacent to waterbodies where access points are required, widening of the roadway to provide the recommended grading for gating terminals is not practical as it may require placing fill into the waterway.
Non-gating crash cushion options for W-beam and concrete barriers are available that could be used on each side of an access point. One disadvantage to these systems is that crash cushions are typically very expensive to install and require widening of the roadway in advance and along the system and flatter traversable slopes perpendicular to the roadway for the systems to perform as designed. Another disadvantage to these systems is that they are expensive to maintain. Another disadvantage to these systems is that they can be expensive to repair after impacts, dependent on severity and type of impact, and type of system (many use crushable cartridges). Another disadvantage to these systems is that they are also not aesthetically pleasing.
The National Highway Traffic Safety Administration (NHTSA) in the United States has been conducting frontal crash tests since 1978 to assess occupant protection capabilities of new cars. New vehicles are crashed head-on perpendicular into a non-deformable rigid barrier at 56 km/h (35 mph).
Air bags with lap and shoulder belts for drivers and front passengers have been required by legislation in the United States on cars manufactured since Sep. 1, 1997, and on light trucks and vans manufactured after Sep. 1, 1998. These measures significantly increase the survivability of a frontal crash.
There remained an opportunity for a pedestrian access terminal that relies on the increased safety of vehicles to safely absorb a limited impact in the design of a pedestrian access terminal. There is also a need for a pedestrian access terminal that limits the probability of an arresting frontal impact.
One solution to the foregoing problems was presented in U.S. patent application Ser. No. 17/966,453 for a static (stationary) pedestrian access terminal. An advantage of the embodiments of the static pedestrian access terminal is that it provides a crashworthy terminal system to allow pedestrian access through a gap in a traffic barrier system such as a W-beam guardrail on lower speed roadways that will meet the crash test requirements of the American Association of State Highway Officials (AASHTO) Manual for Assessment of Safety Hardware (MASH) Test Level 1 (50 km/h [31 MPH]). Other advantages of the static pedestrian access terminal invention are that it is less expensive to install as it does not require extensive widening of the roadway in advance of installation. Other advantages include that it is less expensive to maintain, less expensive to repair and that it is aesthetically pleasing.
An additional advantage of an embodiment of that invention is that it provides a replaceable endcap for attachment to the pedestrian access ends of the terminal blocks for the system to be used on moderate speed roadways that will meet the crash test requirements of AASHTO MASH Test Level 2 (70 km/h [43 MPH]). However, the energy absorbing endcap design is limited in its ability to absorb energy from vehicular impact due to the stationary nature of the static terminal blocks on which the endcaps are mounted. It thus relies primarily on the vehicles' ability to safely absorb a limited impact. Because speeds and weights of impacting vehicles vary widely, the impact required for the vehicle to absorb may exceed the amount the vehicle is capable of absorbing. It further suffers from the external exposure of the compressible endcap to the elements, which result in a shortened lifespan.
Therefore, there remains a need to provide a pedestrian access system that has many of the benefits of the disclosure of U.S. patent application Ser. No. 17/966,453, but with the ability to absorb a greater amount of energy upon impact, to reduce reliance of the energy absorbing characteristics of the vehicle, to provide a safer system for occupants of the vehicle.
The disclosure of U.S. patent application Ser. No. 17/966,453 obtains its benefits by presenting a pair of opposing stationary terminal blocks of significant weight, secured to foundation posts that extend deep below the surface, and that are tethered together by a tensioning member. Soil plates and subsurface positioning of the terminal blocks further resists movement of the terminal block on impact. The system is designed to prevent any movement of the terminal blocks on impact with a vehicle.
The present invention provides an alternative to the fundamental design principal of stationary terminal blocks, embodied in the disclosure of U.S. patent application Ser. No. 17/966,453. The present disclosure discloses a dynamic pedestrian access terminal having range-limited translatable terminal blocks that define an access for pedestrians. In essence, the present disclosure represents a reversal of the engineering principals relied upon in the disclosure of U.S. patent application Ser. No. 17/966,453. The purpose of the reversal is to significantly increase the amount of energy absorbed by the system as a means of lowering the amount of energy required to be absorbed by the impacting vehicle, while still preventing destructive collapse of the pedestrian access path.
The objective is achieved by utilizing the substantial weight of the terminal blocks, translated against the resistance of a compressible attenuator. The purpose may very affectively be achieved by incorporation of a parallel system of compressible attenuators. This allows for greater energy absorption over a short distance to accommodate more energy absorption by the attenuators within the limited allowable translation within the structural confines of the terminal block design, that must also prevent collapse of the pedestrian path.
In summary, the disclosed invention provides a unique solution to the engineering constraints and challenges of providing a pedestrian access terminal that protects pedestrians, prevents gating destruction to the terminal, and is cost effective to install, maintain, and repair. The disclosed invention provides the benefits listed above while first and foremost maintaining the safety of the vehicle occupants where installed. The disclosed invention safely and economically overcomes the aforementioned disadvantages.
The advantages and features of the embodiments presently disclosed will become more readily understood from the following detailed description and appended claims when read in conjunction with the accompanying drawings in which like numerals represent like elements.
A new and improved design for a pedestrian access terminal is disclosed. In one embodiment, the pedestrian access terminal is comprised of a right side and a left side terminal block spaced apart for pedestrian passage along a roadway. Each terminal comprises a top and an opposite bottom, an access end, and an opposite non-access end, and a traffic side and an opposite field side. A portal extends from the top to the bottom. Portal slots extend through the traffic side of each terminal block to intersect the portal.
A pair of foundation posts is positioned below the surface and extend above the surface and into the portal of each terminal block. Portal fasteners are positioned in the portal slots of the traffic side and connected to the foundation posts in each terminal block. A tensioning member may be extended between the foundation posts, beneath the terminal blocks.
In another embodiment, an access chamber extends through the top of the terminal block adjacent to the portal. The access chamber terminates inside the terminal block. Chamber slots extend from the traffic side and the field side of the terminal block to the access chamber. Chamber fasteners located in the chamber slots connect a traffic barrier to the terminal block.
In another embodiment, a relief is inscribed on the bottom of the terminal block. The relief intersects the portal opening at the bottom of the terminal block. The tensioning member is located in the relief of the terminal block and is anchored against the foundation post of each terminal block.
In another embodiment, a pair of lifting anchors is connectable to the top of each terminal block. A cover plate sufficiently large to cover the portal and the access chamber on the top of the terminal block is provided. The cover plate has a pair of cover ports. Cover fasteners are located in the cover plate and connectable to the lifting anchors to secure the cover plate to the top of the terminal block.
In another embodiment, an energy absorbing endcap is attached to the access end of the terminal block.
In another embodiment, the foundation post is a hollow rectangular tubular, having a first pair of opposing sides, one of which is a traffic side. The foundation post has a second pair of opposing sides, one of which is an access side. Block fastener ports extend through the first pair of opposing sides. The portal fasteners pass through the portal slots and into the portal to connect the traffic barrier and foundation post to the terminal block.
In another embodiment, a tensioning portal extends through the second pair of opposing sides of each foundation post. In one embodiment, the tensioning member is a threaded steel rod that extends through the tensioning portal of each foundation post. The tension on the tensioning member may be adjusted by means of an internally threaded fastener located on the ends of the tensioning member, outside of one or both foundation posts.
In another embodiment, the tensioning member includes a wire rope portion that extends through the tensioning portal of each foundation post. A swage button is connected to the end of each wire rope portion. A plate washer anchors the swage button of each tensioning member against the foundation post to allow the tensioning member to be tensioned as between the foundation posts.
In another embodiment, plate fastener ports extend through the second pair of opposing sides of the foundation post, beneath the tensioning portal. A soil plate is provided, with fastener ports in alignment with the plate fastener ports. Soil plate fasteners are located through the fastener ports of the soil plate and the plate fastener ports of the foundation post to secure the soil plate to the foundation post.
More recently, a new design for a pedestrian access terminal was invented, utilizing many of the structural elements of the design described above, but departing from the operating principles of the above design. Specifically, the new invention provides an alternative to the fundamental design principal of stationary terminal blocks, embodied in the disclosure described above. In essence, the present disclosure represents a reversal of the engineering principals relied upon in the disclosure of U.S. patent application Ser. No. 17/966,453. The purpose of the reversal is to significantly increase the amount of energy absorbed by the system as a means of lowering the amount of energy required to be absorbed by the impacting vehicle, while still preventing destructive collapse of the pedestrian access path. This new design is more effective in addressing higher impact forces from higher speed collisions.
The objective is achieved by utilizing the substantial energy required to translate the heavy terminal blocks against the resistance of a compressible attenuator. The purpose may be further achieved by incorporation of a parallel system of compressible attenuators. This allows for greater energy absorption over a short distance to accommodate more energy absorption by compressible attenuators within the limited structural confines of the terminal block design, while preventing collapse of the pedestrian path.
In one embodiment, a pedestrian access terminal is disclosed comprising a right side and a left side terminal block. Each terminal block comprises a top and an opposite bottom, with the bottom positioned beneath the surface of the road. Each terminal has an access end between which pedestrians may pass, and an opposite non-access end, which may be connected to roadside barriers. Each terminal block has a traffic side and an opposite field side. A portal extends from the top to the bottom. A compression chamber extends from the top to the bottom, immediately adjacent to the portal.
Foundation posts extend from below a ground surface to the inside of the portal of each terminal block. An internal attenuator is located inside the compression chamber. The internal attenuator absorbs energy when compressed between the anchored foundation post and the terminal block by translation of the terminal block upon impact by a vehicle.
In another embodiment, a plurality of portal slots extend through the traffic side of each terminal block to intersect the portal. Portal fasteners are located in the portal slots and connect each foundation post to a terminal block. The terminal blocks are translatable in relation to the foundation posts that extend into the portals. The slot configuration of the portal slots permit translation of the portal fasteners without disengagement when the terminal block is impacted by a vehicle.
In another embodiment, an access chamber extends through the top of the terminal block adjacent to the portal. The access chamber terminates internal to the terminal block. Chamber slots extend from the traffic side and the field side of the terminal block to the access chamber, and chamber fasteners located in the chamber slots connect the traffic barrier to the terminal block. The slot configuration of the chamber slots permits translation of the chamber fasteners without disengagement when the terminal block is impacted by a vehicle.
In another embodiment, a recess is located at an intersection of the bottom and the non-access end of the terminal block. An external attenuator is located in the recess. A tray encloses the external attenuator between the recess and the tray. The external attenuator absorbs energy when compressed between the tray, held stationary by the soil, and the terminal block by translation of the terminal block upon impact by a vehicle.
In another embodiment, a plurality of tray slots extend into the terminal blocks proximate the recess. Tray fasteners are located in the tray slots and connect each tray in translatable relation to one of the terminal blocks. The slot configuration of the tray slots permits translation of the tray fasteners without disengagement when the terminal block is impacted by a vehicle.
In another embodiment, the recess has a width equal to a width of the compression chamber. In another embodiment, the internal attenuator has a width equal to a width of the external attenuator. This permits parallel actuation of the internal and external attenuators.
The following description is presented to enable any person skilled in the art to make and use the invention and is provided in the context of a particular application and its requirements. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present invention. Thus, the present invention is not intended to be limited to the illustrated and described embodiments but is to be accorded the widest scope consistent with the principles and features disclosed herein.
A static pedestrian access terminal 1 is disclosed in
A tensioning member 80 is connected between foundation posts 40 to further recess lateral movement of terminal block 10 when struck by a vehicle. Tensioning member 80 and soil plates 60 are located beneath road surface 2 (see
Terminal blocks 10 are typically made of precast concrete and have a mass of between 3,000 and 3,600 lbs. In one embodiment, terminal blocks 10 are located at a distance of about 3.3 (1.0) apart. In one embodiment, a bottom 14 (see
Field tests have proven that a mass of between 3,000 and 3,500 lbs. for terminal block 10, when used in combination with soil plate 60, tensioning member 80, foundation post 40, and related design features, will resist significant lateral movement upon impact with a vehicle weighing 5,000 lbs. travelling at up to 31 mph. Full scale crash tests have further proven that when modern passenger vehicles such as a quad-cab pickup truck with a weight of 5,000 pounds and a small car with a weight of 2425 pounds as specified by AASHTO MASH with impact the terminal block at a speed of 50 km/h [31 mph] at 25 degrees according to AASHTO MASH Test Level 1, vehicle occupants will be protected.
Finally, though reversible, terminal block 10 has a traffic side 20 and a field side 22 when placed in position beside a roadway. As best seen in
Referring back to
In the embodiment illustrated, terminal 10 has an access chamber 28. Chamber 28 extends through the top of terminal block 10 adjacent to portal 26. Chamber 28 terminates internal to terminal block 10. Chamber orifices 34 extend through traffic side 20 of terminal block 10 to intersect with chamber 28. Chamber orifices 34 may also extend through field side 22. In this configuration, terminal block 10 is reversible with regard to chamber orifices 34 and in relationship to the roadway. Chamber fasteners 38 located in chamber orifices 34 further secure terminal block 10 to barrier transition 100.
Also, in the embodiment illustrated, soil plates 60 are attached to one or both sides of foundation post 40 beneath terminal block 10. Fastener ports 66 (see
As seen in
As seen in
As seen in
Block fastener ports 46 extend through the first pair of opposing sides of foundation post 40. As best seen in
A tensioning portal 50 extends through the second pair of opposing sides 44 of each foundation post 40. Tensioning portal 50 of each foundation post 40 receives tensioning member 80. In one embodiment, best seen in
In an alternative embodiment best seen in
A plate washer 92 anchors swage button 82 at each end of tensioning member 80 against foundation post 40 to allow tensioning member 80 to be tensioned as between foundation posts 40.
Referring back to
Plate fasteners 68 are positioned through plate fastener ports 48 and fastener ports 66 to secure soil plate 60 to foundation post 40. Block side 64 of soil plate 60 is optional. When used, block side 64 facilitates the advantageous three-way alignment of this embodiment by abutment with terminal bottom 14 of terminal block 10. In this manner, assembly of pedestrian access terminal 1 is expedited.
Pre-tensioning of opposing terminal blocks 10 to each other provides a greatly enhanced resistance to displacement of either terminal block 10 by a vehicle leaving the roadway. The flexibility of the disclosed tensioning member 80, which is provided by wire rope sections 84, provides enhanced assembly of pedestrian access terminal 1. The minimal size of tensioning member 80 further provides for rapid and cost-effective subterranean location of tensioning member 80. Tensioning member 80 anchors the impacted terminal block 10 to the non-impacted terminal block 10, resisting bending of foundation post 40 and preventing movement of the pedestrian access terminal 1 on impact.
With terminal block 10 aligned with foundation post 40, connection of transition 100 to terminal block 10 is easily facilitated. By replacing cover plate 70 over portal 26 and chamber 28, access to fasteners 36 and 38 is not possible and pedestrian access terminal 1 becomes tamper resistant. Having chamber 28 terminate interior to terminal block 10 provides the advantage of preventing loss of fasteners and tools through the interior of terminal block 10 during assembly.
Terminal blocks 10 rest on soil plates 60 attached to foundation posts 40. Force applied in a collision to one end of tensioning member 80 would normally apply a bending moment on the opposing foundation post 40. In the configuration as designed and disclosed, foundation post 40 is fortified against bending by engagement within terminal block 10, tensioning member 80, and soil plate 60.
The addition of energy absorbing endcap 120 is intended to work in conjunction with the crushing of the front of the passenger vehicle during impact at a velocity in excess of the IIHS requirement of 64.5 km/h [40 mph] to achieve a successful test under MASH TL-2 (passenger vehicles including 5,000 pound quad-cab pickup truck and 2,425 pound small car impacting the terminal block at 70 km/h [43.4mph] at 25 degrees).
The design for a dynamic pedestrian access terminal 200 is disclosed in
A pair of opposing terminal blocks 210 is provided with a passage 3 to permit pedestrians to pass between them. Each terminal block 210 is mounted to a foundation post 40, to which it is attached by fasteners 236. A soil plate 60 is mounted to each side of foundation post 40 to help resist lateral movement of foundation post 40 when terminal block 210 is struck by a vehicle. For this purpose, soil plates 60 face the pedestrian passage 3 between terminal blocks 210.
In the embodiment illustrated, terminal blocks 210 are positioned subsurface, such that a terminal bottom 214 (see
Terminal blocks 210 are typically made of precast concrete and have a mass of between about 3,000 and 3,600 lbs. In one embodiment, terminal blocks 210 are spaced at a distance of about 3.3 feet (1.0 meter) apart. As best seen in
Referring ahead to
Though reversible, terminal block 210 has a traffic side 220 and a field side 222 when placed in position beside a roadway. As seen in
As best seen in
Unique to the present disclosure, a compression chamber 240 extends through terminal top 212 and terminal bottom 214 between the access end 216 of terminal block 210 and portal 226. As shown in the embodiment illustrated, compression chamber 240 and portal 226 form a unitary passage vertically through terminal block 210.
In
Unique to this embodiment, portal fasteners 236 are located horizontally translatable within portal slots 232 and in horizontally translatable relationship to terminal block 210. This connection permits limited translation of terminal block 210 without requiring deformation of foundation post 40, or demolition of portal fasteners 236 or transition 100.
In the embodiment illustrated, terminal 210 has an access chamber 228. Access chamber 228 extends through the top of terminal block 210 between portal 226 and the no-access end 218 of terminal block 210. Access chamber 228 may terminate internal to terminal block 210. Chamber slots 234 extend through traffic side 220 of terminal block 210 to intersect with access chamber 228. Chamber slots 234 may also extend through field side 222. In this configuration, terminal block 210 is reversible with regard to chamber slots 234 and in relationship to the roadway. Chamber fasteners 238 located in chamber slots 234 further secure terminal block 210 to barrier transition 210.
Unique to this embodiment, chamber fasteners 238 are located horizontally translatable within chamber slots 234 and in horizontally translatable relationship to terminal block 210. This connection permits limited translation of terminal block 210 without requiring demolition of chamber fasteners 238 or transition 100.
As seen in
Referring to
In one embodiment, a compression chamber 240 and portal 226 are co-formed as rectilinear. Referring to
As disclosed in the embodiment illustrated, where foundation post 40 substantially fills portal 226, WC is at least as wide as WP to allow translation of terminal block 210 rearward (towards no-access end 218) in relationship to foundation post 40 on impact of a vehicle with terminal block 210. Similarly, allowing foundation post 40 to fill portal 226 allows translation of terminal block 210 to be guided by the path for foundation post 40 into compression chamber 240 on impact of a vehicle with terminal block 210.
Still referring to
Allowing length LRto be substantially equal in length to LC permits full compression of internal attenuator 270 and external attenuator 280 in parallel force resistance to translation of terminal block 210. The length relationship between length LP and lengths LC and LR can be varied to control the desired amount of translation of terminal block 210 for response optimization.
Referring to
As seen in
Block fastener ports 46 extend through the first pair of opposing sides of foundation post 40. As best seen in
As best seen in
Referring back to
Plate fasteners 68 are positioned through plate fastener ports 48 and fastener ports 66 to secure soil plate 60 to foundation post 40. If used, block side 64 of soil plate 60 facilitates the advantageous three-way alignment of this embodiment by abutment with terminal bottom 214 of terminal block 210. In this manner, assembly of pedestrian access terminal 200 is expedited.
Internal attenuator 270 compresses against foundation post 40. Movement of foundation post 40 is limited by its embedment in the ground below surface 2, and further tension applied to tensioning member 80 which is anchored to the non-impacted terminal block 210. External attenuator 280 compresses against tray 260. Movement of tray 260 is limited by its engagement with the ground as it is located beneath surface 2.
This novel configuration allows limited, dynamic translation of terminal block 210 in response to a vehicle impact without collapse of the pedestrian passage 3 between terminal blocks 210. The significant total energy required to move the substantial weight of a terminal block 210 and compressing internal attenuators 270 and external attenuators 280 represents a very substantial absorption of energy that would otherwise be absorbed by contraction of the impacting vehicle and impact forces on its occupants. The present disclosure provides an embodiment with parallel attenuators, including internal attenuator 270 and external attenuator 280. Compression of attenuators 270 and 280 is limited to the volumes of compression chamber 240 and recess 250, and their respective lengths LC and LR.
In an embodiment with terminal block 210 located partially subsurface, as in
Internal attenuator 270 make be of a like or dissimilar material and structure to that of external attenuator 280, to achieve different acceleration responses to impacts, or to balance responses realized by the differences in the volumes of internal attenuator 270 and external attenuator 280.
As used herein, the term “substantially” is intended for construction as meaning “more so than not”.
Having thus described the present invention by reference to certain of its preferred embodiments, it is noted that the embodiments disclosed are illustrative rather than limiting in nature and that a wide range of variations, modifications, changes, and substitutions are contemplated in the foregoing disclosure, and in some instances, some features of the present invention may be employed without a corresponding use of the other features. Many such variations and modifications may be considered desirable by those skilled in the art based upon a review of the foregoing description of preferred embodiments. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.
This application is a continuation in-part claiming priority to U.S. patent application Ser. No. 17/966,453, filed Oct. 14, 2022.
Number | Date | Country | |
---|---|---|---|
63255760 | Oct 2021 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 17966453 | Oct 2022 | US |
Child | 18641160 | US |