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Question
State	KS
Description Text	I was doing some research on the pooled fund site on a separate topic and came across a detail showing a wood post alternative for the MGS thrie-beam (see attached .png file). I thought this was still in development/hadn’t been finalized yet. Can you confirm the “recommended wood post design for Tested MWTSP approach transition” details shown in the attachment would apply to KDOT’s current MGS thrie-beam (standard drawing RD613A, also attached)? If we can have this as a wood post option can you confirm the blockouts for the thrie-beam are still 6” wide for the 8” wide x 10” deep 7’-0” long posts? Depending on your response I may put together some draft standard drawings for MwRSF review before KDOT implements them.

Question

State

KS

Description Text

I was doing some research on the pooled fund site on a separate topic and came across a detail showing a wood post alternative for the MGS thrie-beam (see attached .png file). I thought this was still in development/hadn’t been finalized yet. Can you confirm the “recommended wood post design for Tested MWTSP approach transition” details shown in the attachment would apply to KDOT’s current MGS thrie-beam (standard drawing RD613A, also attached)? If we can have this as a wood post option can you confirm the blockouts for the thrie-beam are still 6” wide for the 8” wide x 10” deep 7’-0” long posts? Depending on your response I may put together some draft standard drawings for MwRSF review before KDOT implements them.

System Performance Evaluation

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Approach Guardrail Transitions (AGTs)

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System Features

Date September 24, 2015
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Attachment MGS Wood Posts.png Attachment rd613a.pdf

Response
Response (active)	A few comments: The drawing for “Recommended Wood Post Design for Tested MWTSP Approach Transition” (bottom sketch on the drawing page you forwarded) appears to be very similar to the steel post transition from RD613A. You would just need to swap the 3 larger steel posts on the downstream end for the larger 8”x10”x6.5-ft wood posts shown in the drawing. The blockouts can remain the same size – 6”x8”x19” (your email had a 10” height, but I assume that was a typo). Just a comment/question on your current steel post transition… What size posts are you utilizing for the three 7-ft long posts adjacent to the buttress? I don’t see a section note for the posts on the drawing set (other than on section C for the w-to-thrie transition element). Nearly all transitions with 37.5” post spacing adjacent to the rigid buttress require increased post sections, e.g., W6x15’s, W6x25’s, etc.). I am unaware of any transition being designed and tested utilizing only W6x9 posts with a 37.5” post spacing.

Response

Response
(active)

A few comments:

The drawing for “Recommended Wood Post Design for Tested MWTSP Approach Transition” (bottom sketch on the drawing page you forwarded) appears to be very similar to the steel post transition from RD613A. You would just need to swap the 3 larger steel posts on the downstream end for the larger 8”x10”x6.5-ft wood posts shown in the drawing. The blockouts can remain the same size – 6”x8”x19” (your email had a 10” height, but I assume that was a typo).

Just a comment/question on your current steel post transition… What size posts are you utilizing for the three 7-ft long posts adjacent to the buttress? I don’t see a section note for the posts on the drawing set (other than on section C for the w-to-thrie transition element). Nearly all transitions with 37.5” post spacing adjacent to the rigid buttress require increased post sections, e.g., W6x15’s, W6x25’s, etc.). I am unaware of any transition being designed and tested utilizing only W6x9 posts with a 37.5” post spacing.

Date September 25, 2015
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Response
Response (active)	Thanks for the quick reply. I’m going to use TRP-03-243-11 as a reference to put the details together for a wood post option. KDOT’s 7’-0” posts are W6 x 15 posts. That information is shown on a post details sheet, which I didn’t send over yesterday. Once I have the draft drawings put together can I send them onto you for review?

Date September 26, 2015
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KDOT Thrie-Beam Standard Drawing