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Here at Kentucky, we are using more and more Thrie Beam in our roadway designs. Normally we are tying it to our bridges, so we haven't ran into this issue, but we have begun to use them on our roadsides to shield obstacles and we have ran into how to end our Thrie Beam Guardrail.  Currently, we are telling people to transition back down to MGS, then add a W Beam End Anchor. 

In talking to Jeff, we dug into your Report TRP-03-279-13 - Downstream Anchoring requirements for the Midwest Guardrail Systems.  It looks like some states have used the same configuration and transferred them to Thrie Beam - i.e. IowaDOT - BA203 & 204 (attached).

After thinking it through, it makes sense to transfer the Cable Assembly, Soil Plate, and Foundation Tube to the Thrie Beam Guardrail. So I just wanted to get your opinion on this.

Thank you for any help you can provide!

No current trailing end anchorage or end terminal design has been full-scale tested for use with thrie beam guardrail. Thus, we have typically recommended that field installations of thrie beam guardrail transition to MGS guardrail at the end of the system and then employ a MASH tested trailing end anchorage or end terminal design. We provided a lot of guidance on this in the report linked here - https://mwrsf.unl.edu/researchhub/files/Report381/TRP-03-417-20.pdf

That said, a trailing anchorage for thrie beam could be done. We used a mocked-up version during testing of the bullnose. See details in the report below. Note that the bullnose used dual anchors because of the way it is loaded, but a thrie beam end anchorage would not require two cable anchor assemblies. The biggest differences between the Iowa detail and the one we used in the bullnose is that the cable anchor bracket is attached to the upper valley, and we used dual foundation tubes and groundline strut consistent with the MGS trailing end anchorage that was tested to MASH. Thus, if one wanted to use a thrie beam end anchorage, we would recommend using something more like that to be more consistent with the MASH tested system.

Again, it should be noted that no thrie beam end anchorage has been tested to MASH.

https://mwrsf.unl.edu/researchhub/files/Report393/TRP-03-418-20.pdf

Here is the original MASH tested W-beam end anchorage.

https://mwrsf.unl.edu/researchhub/files/Report279/TRP-03-279-13.pdf

https://mwrsf.unl.edu/researchhub/files/Report423/TRP-03-370b-20.pdf

Let me know if you need anything else.

Thanks!