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Can an MGS Approach Transition be Connected to a Anchored Temporary Barrier?

Question
State	WI
Description Text	Can an MGS Approach Transition be Connected to a Anchored Temporary Barrier?

System Performance Evaluation

System Types
Approach Guardrail Transitions (AGTs)
Portable Barriers

Applications

System Features

Date September 12, 2019
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Attachment 2019-09-12 Approach Transition and Anchored Temporary Barrier v1.pdf

Response
Response (active)	At this time, we cannot recommend the attachment of thrie beam AGTs to anchorage portable barrier systems. While a thrie beam AGT may be able to effectively transition the stiffness between a guardrail system and an anchored PCB system, there would be concerns for snag on the toe of the anchored PCB at the connection between the AGT and the PCB. Currently, the buttress or bridge rail at the attachment for crash worthy thrie beam AGTs utilize a shape transition, tapered end sections, and/or curbs to reduce the snag on the end of the concrete parapet. Attachment of a thrie beam AGT would have similar concerns with respect to the end of the PCB system. Thus, one would need to modify the shape of the end of the PCB section, offset the approach guardrail, or use some form of snag mitigation hardware to mitigate the concern. A previous research project at MwRSF did develop a transition from the MGS to free-standing PCB. During that effort, concepts were developed for anchoring the PCBs and attaching a stiffened guardrail section. However, this was abandoned due to the added complexity over the final design that was chosen. https://mwrsf.unl.edu/researchhub/files/Report299/TRP-03-300-14.pdf https://mwrsf.unl.edu/researchhub/files/Report330/TRP-03-335-17.pdf

Response

Response
(active)

At this time, we cannot recommend the attachment of thrie beam AGTs to anchorage portable barrier systems. While a thrie beam AGT may be able to effectively transition the stiffness between a guardrail system and an anchored PCB system, there would be concerns for snag on the toe of the anchored PCB at the connection between the AGT and the PCB. Currently, the buttress or bridge rail at the attachment for crash worthy thrie beam AGTs utilize a shape transition, tapered end sections, and/or curbs to reduce the snag on the end of the concrete parapet. Attachment of a thrie beam AGT would have similar concerns with respect to the end of the PCB system. Thus, one would need to modify the shape of the end of the PCB section, offset the approach guardrail, or use some form of snag mitigation hardware to mitigate the concern.

A previous research project at MwRSF did develop a transition from the MGS to free-standing PCB. During that effort, concepts were developed for anchoring the PCBs and attaching a stiffened guardrail section. However, this was abandoned due to the added complexity over the final design that was chosen.

https://mwrsf.unl.edu/researchhub/files/Report299/TRP-03-300-14.pdf

https://mwrsf.unl.edu/researchhub/files/Report330/TRP-03-335-17.pdf

Date September 19, 2019
Previous Views (154) Favorites (0)