View Q&A



Steel Post for Trailing End Anchor - Breaker Arm Assembly - Fabrication Questions, plus other smaller questions

Question
State MN
Description Text

Hi,



The attached detail shows our proposed standard for Standard Plate 8363, Steel Post Trailing End Anchor (per TRP-03-370b-20).  We received feedback from our fabricators and want to run this by you for your input. 



 



They have requested we add galvanization weep/drain holes to the following components:



Lower Post Top Plate (Sheet 3 of 5)



-Add ½”  dia. hole to Lower Post Top Plate,  as shown 6.5” from bolt hole.



8” Length Square Tube (Sheet 6 of 6)



                -Add  two 1” dia. holes on adjacent sides of the tube.



Breaker Arm Plate (Sheet 6 of 6)



                -Add one 1” dia. hole, located in the center of the plate.



If these holes can be provided for their use, what is the appropriate size and location?



 



They have also requested an additional weld where the 15” Length Square Tube attaches to the Breaker Arm Plate.  (Sheet 5 of 6, Section D-D.)  



At present it appears the only welds connecting the 15” Length Square Tube to the Breaker Arm Plate is at the gussets.  We’re assuming it’s the same 3/16” welds but if it is not please let us know.



 



Thank you for the help in this matter. Let us know if you have any questions or would like to discuss over the phone.



MASH
TL-3

W-beam Guardrails

End Treatment,Terminals and Anchorages
Midwest Guardrail Systems (MGS)

Galvanization and Surface Treatments

Date January 23, 2023
Previous Views (18) Favorites (0)
Attachment 8363_Proposed_Fabricator_Comments.pdf
Response
Response
(active)

Hello, 

We have responded to your questions below in red. 

 

The attached detail shows our proposed standard for Standard Plate 8363, Steel Post Trailing End Anchor (per TRP-03-370b-20).  We received feedback from our fabricators and want to run this by you for your input. 

They have requested we add galvanization weep/drain holes to the following components:

Lower Post Top Plate (Sheet 3 of 5)

-Add ½”  dia. hole to Lower Post Top Plate,  as shown 6.5” from bolt hole.

Addition of the weep hole to the lower post top plate should not be an issue. We previously did this with the USPB posts for the steel post thrie beam bullnose system. In that case we allowed up to a 13/16” diameter hole. See Q?&A at this link - https://mwrsf.unl.edu/q&a/view.php?id=1211

8” Length Square Tube (Sheet 6 of 6

-Add  two 1” dia. holes on adjacent sides of the tube.

The addition of these holes for flow of the galvanization should not be an issue and will not compromise the integrity of the tube assembly.

Breaker Arm Plate (Sheet 6 of 6)

-Add one 1” dia. hole, located in the center of the plate.

The addition of this hole for flow of the galvanization should not be an issue and will not compromise the integrity of the tube assembly.

If these holes can be provided for their use, what is the appropriate size and location?

In the past, we have spoken with galvanizers that the holes should be at least ¾” diameter to allow for proper flow. Keeping the hole diameter 1” or less should help limit the effect on the structural capacity of the assemblies.

They have also requested an additional weld where the 15” Length Square Tube attaches to the Breaker Arm Plate.  (Sheet 5 of 6, Section D-D.)  

At present it appears the only welds connecting the 15” Length Square Tube to the Breaker Arm Plate is at the gussets.  We’re assuming it’s the same 3/16” welds but if it is not please let us know.

For the actual test installation, the base of the tube was welded to the plate with a 3/16” fillet weld all the way around the base of the tube. It was omitted from the drawing details in error. We will update the details and the report to reflect this. Feel free to add the weld to your details.


Date January 24, 2023
Previous Views (18) Favorites (0)
Attachment DSC_0025.JPG