Bearing stiffener question 1

[bridgeengineer2007]

The bearing stiffener on a steel plate girder has been misconstructed and is offset ~ 1 3/8" closer to the center of the span from the line of bearing. Therefore the line of bearing is not acting directly on the bearing stiffener.

What kind of check should be performed? There is now an induced eccentric moment on the bearing stiffener, but I am more concerned with the fact that tension field action no longer applies and that the shear due to the reaction will act soley on the plate girder section, which I imagine will fail because the beam was designed with intermediate stiffeners - i.e., with the offset reaction, the shear no longer passes through an "end panel" as described in AASHTO.

Any thoughts?

The beam now looks like this, with the offset bearing stiffener at the left end (vertical lines are stiffeners):

_____|_____|_____|_____|_____|_____|_____
^ ^

 

[bridgebuster]

I haven't designed bearing stiffeners lately and I don't have AASHTO with me. But I recall the design is taken as a column using the properties of the web and the stiffener. My gut feeling is 1 3/8" isn't going to matter. Try checking the web alone if that doesn't work treat it as an column with a moment.

 

[dhengr]

blc219:
1.375" might not be a big deal on a 10' deep plate girder, and it may be a big deal on 3' deep plate girder. A meaningful sketch of the detail with some dimensions, loads, etc. would be most helpful in conveying what you are dealing with. I’m not condoning poor fab. tolerances, but can you still make it work? Can you still rationalize and justify the loads and stresses up into the girder web. Is the bearing stiffener still over the bearing plate, even though 1.375" out of position? What does a bearing stiffener really do? It provides sufficient net bearing area on top of the flange, and over the bearing and/or bearing plate, to take that concentrated load up into the web of the plate girder, without too high a bearing stress at the top of the flange plate. Then, acting as a column section, along with the web plate it must take that load up into the web without buckling.

 

[bridgebuster]

blc219:

Out of curiosity, why were vertical stiffeners used instead of going with a thicker web?