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Pier wall for Zone of Intrusion

State IA
Description Text

We are looking at using an existing shoulder as a traffic lane during peak times.


Having an Zone of Intrusion distance is difficult in the tight footprint.

Do you you know of any wall / pier system that could replace the ZOI for a barrier?


Would a taper to a high pier wall work..?


see attached - existing, rough concept.




Existing not much ZOI there, but we want to reduce it further.


Permanent Concrete Barriers
Stiffness and Height Transitions

Date October 6, 2022
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Attachment pierwall.jpg Attachment zoi pier.png

In terms of preventing vehicle extension into the piers, we do believe that sloping the barrier upward can help mitigate the ZOI. It depends what vehicle type you are looking to keep out of the piers.


For passenger vehicles, we believe that sloping the barrier upward at a 6:1 taper does not create a safety issue for impacting vehicles based on similar height transitions we have used for AGT buttresses. We have also noted that a height of 48” should mitigate the extension of passenger vehicles beyond the top face corner of the barrier.


See the attached response from the Q&A site as an example.


If you desire to shield the piers from heavy vehicles like the TL-4 SUT or TL-5 tractor trailers, the problem becomes more difficult as the height required to reduce the ZOI is difficult to achieve and the box lean is an issue. We have discussed that issue to some degree previously through the Q&A as well.


Date October 31, 2022
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