huangyhg

bridge crane building frame drift limitations
all,
can anyone point me towards criteria that limits the building drift for bridge crane loads? i found the canadian criteria, 50mm or l/240 but nothing else.
the us document is asce design guide 7 "industrial buildings" part 2 is about crane support. chapter 16 has the following serviceability requirements.
1. pendant operated cranes frame drift less than runway height divided by 100.
2. cab operated cranes - frame drift less than runway height over 240 or 2" based on 10 year wind speed or crane lateral loads on bare frame.
there are other criteria for multiple bays of cranes.
correction aisc design guide no. 7.
i also looked at design guide 3, "serviceability design considerations for steel buildings", pg 42, which states h/240 for pendant and h/100 for cab operated, both not to exceed 1" max. any thoughts why this differs?
part of it could be the expected use of the crane. a cab operated crane certainly should have tighter tolerance on drift than a pendant operated crane so either dg3 or your quote is backward. the difference between 2" and 1" overall limitation i can't explain. for mill cranes aise tech report #13 "guide for design and construction of mill buildings" section 5.3 requires limiting lateral drift to "1/400 of the height from column base or 2 in. whichever is less" for crane horizontal loads or 10 year wind load. aise has tighter ratio but maintains the 2" overall maximum criteria. i would tend to go with h/240 and 2" maximum for a cab operated crane unless you are designing a steel mill building.

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