crane runway beam column seat connection bolts
crane runway beam column seat connection bolts
(OP)
As seen from the attached photos (pic-1 and pic-3) some of the crane runway beam bolts ruptured and runway beam bottom side moved.
This problem occur only in one beam connection and same connection detail used along the facility.
I need to find out the reasons behind this problem and since yesterday I found several alternative reasons as I mentioned below;
- fatigue. (but i don't why only this one not the others.)
- some bolt clearances of 'this' produced plate is different from the attached detail and so several bolts worked alone for runway beam dynamic loads.
- lateral torsional buckling has occurred and lateral force at bottom flange ruptured the bolts.




Any reasons else?
Thanks,
Dogan.
This problem occur only in one beam connection and same connection detail used along the facility.
I need to find out the reasons behind this problem and since yesterday I found several alternative reasons as I mentioned below;
- fatigue. (but i don't why only this one not the others.)
- some bolt clearances of 'this' produced plate is different from the attached detail and so several bolts worked alone for runway beam dynamic loads.
- lateral torsional buckling has occurred and lateral force at bottom flange ruptured the bolts.




Any reasons else?
Thanks,
Dogan.






RE: crane runway beam column seat connection bolts
Looking at the bottom photograph, it doesn't appear the shim pack is fully compressed which would support the possibility the bolts were not installed and tightened properly.
The second photo from the top seems to indicate the bolts were not the correct length, thus there is less engagement than the full nut.
The top photograph appears to show the wrong type of fasteners were used.
Best regards - Al
RE: crane runway beam column seat connection bolts
It is not a good design per the circled connection in the pdf file. The configuration restraints the crane beam end from rotating, and therefore the bolts or the crane beam will experience fatigue damage. Of course, it also depends on the crane work class. The connection may be not critical for light work class crane. And there is no lateral supports on the top flange of crane beam ends. For your information: “Crane-supporting steel structures - design guides” gives some example how to setup the crane connection.
RE: crane runway beam column seat connection bolts
Use properly sized high strength structural bolts and pre-tension them.
RE: crane runway beam column seat connection bolts
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RE: crane runway beam column seat connection bolts
Dik
RE: crane runway beam column seat connection bolts
With continuous crane girders it may be possible that your end-span connection bolt failures are due to tension forces when the crane is in the opposing/adjacent span, causing fatigue effects in the connection.
To troubleshoot the probable-cause it may be worthwhile to up-close visually observe the end-connection when the far-span of the crane girder is traversing under load.
RE: crane runway beam column seat connection bolts
RE: crane runway beam column seat connection bolts
I think that last photo is at the interior support of the 2-span crane girder condition, at inside face of the girder, adjacent to the building column (which is on the extreme RHS of that photo).
RE: crane runway beam column seat connection bolts
Columns in industrial buildings get a lot of abuse. Has there been impact damage at the column bases? This could have resulted in twisting the crane beam bracket.
RE: crane runway beam column seat connection bolts
I did not saw any torch touch Dik. The 3 bolts that you saw on the picture are just temporary ones. They will be changed to preloaded ones as you mentioned.
Yeah, the M24 slotted hole dimensions(25x48) bigger than short slot hole dimensions(27x32) and smaller than long-slot dimensions(27*60) mentioned at AISC 360 Table J3.3M. But I can't say this is the main problem?
RE: crane runway beam column seat connection bolts