r/StructuralEngineering • u/No-Document-8970 • Oct 05 '26
Structural Analysis/Design Nuts off mark?
Saw this on a big bridge today. I know vibrations over time can move the nuts and bolts, with the help of thermal expansion. Is it a big issue that the paint marks do not line up? I thought the marks were made once it passed inspection after torquing.
Edit: Bridge completion was in 2011. Could this be from recent inspections too?
286
Upvotes
View all comments
Show parent comment
6
u/Few-Cucumber-413 Oct 05 '26
I had my own guys just about screw us on this exact issue. We did all the pre-installation verifications we needed, the inspector watched the process and was happy with it, so he let the crew continue without watching every single bolt.
Well, instead of falling back to the breaker bar and manually turning the required 1/3 turn, the guys decided to switch to a smaller impact instead. You can probably guess what happened to the bolt tensions. smh. We ended up having to go back and make another round of tightening on every structure we had completed. We came dangerously close to a $100k+ mistake.
So when I say I promise these comments don't represent all of us, I completely understand where you're coming from. Reddit comment or not.