The process of metal work on a job site.

[jar546]

https://apple.news/Afdz-LTHLQYGY6QPDG3LPYA

 

[jar546]

This one is a great read

 

[BLangley]

Fascinating...will be kicking it over to my engineer cousin...amazing how slight process changes can have huge impacts.

 

[e hilton]

Two important takeaways from the article, both germane to the other discussion about the FIU bridge.
1. Written procedures were not followed. The specs called for the cut openings (the 2x4 weld access holes) to be ground smooth, to bare shiny metal. Didn’t do that. The welding debris contributed to the growth of microcracks.
2. In spite of 2 major beams developing significant cracks, the structure sagged less than one inch ... because of redundant design elements.

 

[ADAguy]

Interesting how this compares to the Sky Bridge collapse 30 years ago where the shop drawings were inadequately reviewed leading to a value engineering change (welded "C" channels vs tube steel substitution) creating a weak point for the threaded support rods and the omission of a secondary washer. In this case there were far more inspections and oversight vs the sky bridge. It was the drywall installers who felt the condition and Tea Dance users who ultimately caused the failure by inducing a wave into the spans by rising and falling (weight on/weight off) while dancing on the bridge.
I am sharing this with our engineers and the Florida bridge collapse findings which have also just appeared elsewhere on our site.