Can't figure out how to reply to a post, so to @Milliontown: "With a few inches of snow and the bus, that was well over the posted weight limit. Interesting to see how this might affect public transportation policy if our vehicles are too large for our aging infrastructure."
26 tons would be...
Many DOT's and Canadian provinces in the "freeze-thaw" zones have been moving away from Epoxy Coated Rebar.
The theory is that the epoxy coating wears down in the alkali environment of the concrete in about 30 years. Based on the concrete cover used on bridges - about 3" (75mm), but depends on...
^ based on the box beam having 1-3/8" (35mm) vertical plates and 1/2" (13mm) top and bottom plates, it takes away from the theory the shear lag is the culprit (with the connection on the vertical plates only.
The source is more likely the weld that formed the box. By the 1970's, they should...
Here is another photo linked above by @azcats : https://www.ardot.gov/wp-content/uploads/2021/05/crack_june2019_michaelbakerintl_hernando-1024x569.jpg
I assume this is the same location, so it appears that the cracking started at the bottom, outer corner. (the current photos show that the...
Does anyone have a clearer image of the bridge drawing? It might show the member forces.
How did they tighten those bolts. Someone had to hold the nut from the inside. I wonder if there is a hand hole anywhere near.
Could there be some torsion in the main tie beam. The main transverse...
That flared beam coming in does appear suspicious. It would add a mid-span reaction to the exterior girder, and also the load is eccentric to the web centre-line, adding a torsion to the main girder as well. At the same time, the same simple cross frame is located on the back-side as exists...
