摘要:
Guardrail installation designs are described that incorporate a box beam rail as the structural rail member. The box beam rail member may have an open cross-section or a closed cross-section. An impact head is provided to bend and deflect the rail member during an end-on collision, allowing the rail member to be deflected away from the roadway and out of the path of an end-on impacting vehicle. The impact head includes a striking face and a chute portion that receives the box beam rail member therewithin. In addition to bending and deflecting the rail member, the impact head may also include a flattening section for flattening the rail member.
摘要:
According to one embodiment, a cable anchor system for an end terminal includes a cable anchor bracket configured to couple to a guardrail, in which the cable anchor bracket includes a flat plate having an aperture formed therein and a plurality of protrusions extending from a plane containing the aperture. The protrusions are configured to releasably engage the guardrail.
摘要:
According to one embodiment, a cable anchor system for an end terminal includes a cable anchor bracket configured to couple to a guardrail, in which the cable anchor bracket includes a flat plate having an aperture formed therein and a plurality of protrusions extending from a plane containing the aperture. The protrusions are configured to releasably engage the guardrail.
摘要:
A locking hook bolt, which may be used for securing cable to support posts in guardrail assemblies, and a method for using the same are provided. The locking hook bolt includes a first leg, a second leg, and an arcuate portion coupling the first and second legs such that the second leg extends generally parallel with, and spaced apart from, the first leg. A locking portion configured to engage a support post extends from, and forms an angle of approximately 90 degrees with, the second leg. The first leg of the locking hook bolt includes a threaded portion opposite the arcuate portion.
摘要:
A guardrail safety system includes a guardrail beam operable to contain and redirect an errant vehicle to prevent the vehicle from leaving a roadway. At least a portion of the guardrail beam includes a thrie beam. A support post is coupled to the guardrail beam and includes a lower portion, a mid portion, and an upper portion. The lower portion is installed below grade adjacent the roadway. The mid portion lies substantially adjacent the grade and is weakened about a first axis without being substantially weakened about a second axis that is generally perpendicular to the first axis. An upper portion is releasably coupled to the guardrail beam such that the upper portion is uncoupled from the guardrail beam when the mid portion yields about the first axis.
摘要:
In accordance with a particular embodiment of the present invention, an end treatment of a guardrail safety system includes a terminal portion of a guardrail beam that has a downstream end and an upstream end. The terminal portion of the guardrail beam slopes from a first vertical height appropriate for redirecting an errant vehicle to a second vertical height proximate the surface of the ground at an upstream end of the terminal portion of the guardrail beam. A flattening portion forms a channel through which the terminal portion of the guardrail beam is disposed. A vertical dimension of the channel is greater at a downstream end of the flattening portion than at an upstream end of the flattening portion. An impact plate is connected to the flattening portion for engaging an impacting vehicle at an end of said guardrail beam. During an end-on impact, the impact plate and the flattening portion are advanced longitudinally along the guardrail in a downstream direction by the vehicle. The advancement of the impact plate and flattening portion dissipate energy to decelerate the impacting vehicle. As downstream portions of the guardrail beam are forced into the flattening portion, the guardrail is flattened vertically.
摘要:
A terminal portion of a guardrail safety system includes a terminal portion of a guardrail beam having a downstream end and upstream end. The terminal portion of the guardrail beam slopes from a height appropriate for redirecting an errant vehicle to a height proximate the surface of the ground at an upstream end of the terminal portion.Support posts are installed adjacent a roadway in spaced apart relation to one another and are coupled to the terminal portion of the guardrail beam. A terminal support post is installed adjacent the roadway at an upstream end of the terminal portion of the guardrail beam. The terminal support post couples to an upstream end of the terminal portion of the guardrail beam by a resistive, tensile coupling that maintains tension in the terminal portion of the guardrail beam. The resistive, tensile coupling is maintained between the terminal support post and the guardrail beam during an end-on or re-directive impact by a vehicle. However, the resistive, tensile coupling between the terminal support post and the guardrail beam is released during a reverse-direction impact.
摘要:
A cable guardrail release system includes a firsts number of anchor posts installed adjacent a roadway. Each of the first number of anchor posts secures an end of a respective cable. Each anchor post is operable to release the respective cable secured by the anchor post upon a vehicle impact to the anchor post. The system may include a length of need section that includes a plurality of intermediate support posts each configured to support each of the respective cables. The length of need section may include portions of each of the respective cables running in between the plurality of intermediate support posts. Each anchor post may be configured to resist release of the respective cable secured by the anchor post upon a vehicle impact to the length of need section generally at an angle to the flow of traffic on the roadway.
摘要:
A terminal portion of a guardrail safety system includes a terminal portion of a guardrail beam having a downstream end and upstream end. The terminal portion of the guardrail beam slopes from a height appropriate for redirecting an errant vehicle to a height proximate the surface of the ground at an upstream end of the terminal portion. Support posts are installed adjacent a roadway in spaced apart relation to one another and are coupled to the terminal portion of the guardrail beam. A terminal support post is installed adjacent the roadway at the upstream end of the terminal portion of the guardrail beam. The terminal support post couples to an upstream end of the terminal portion of the guardrail beam by a resistive, tensile coupling that maintains tension in the terminal portion of the guardrail beam. The resistive, tensile coupling is maintained between the terminal support post and the guardrail beam during an end-on or re-directive impact by a vehicle. However, the resistive, tensile coupling between the terminal support post and the guardrail beam is released during a reverse-direction impact.
摘要:
A cable guardrail release system includes a first number of anchor posts installed adjacent a roadway. Each of the first number of anchor posts secures an end of a respective cable. Each anchor post is operable to release the respective cable secured by the anchor post upon a vehicle impact to the anchor post. The system may include a length of need section that includes a plurality of intermediate support posts each configured to support each of the respective cables. The length of need section may include portions of each of the respective cables running in between the plurality of intermediate support posts. Each anchor post may be configured to resist release of the respective cable secured by the anchor post upon a vehicle impact to the length of need section generally at an angle to the flow of traffic on the roadway.