Allowable crane traction frame drift?

[SteelPE]

I have a building I designed to accommodate a 15ton pendant operated bridge crane. The project ran over budget and the client decided to reduce the size of his building. Unfortunately the portion of the building he decided to eliminate contained a brace used to resist traction forces of the crane. I am now being asked to design a frame that will allow the space under the crane to be open (a moment frame). So I am wondering what the allowable drift of this frame should be?

I am considering using H/400 but I am not sure if this is even correct. All of the literature I have relates to deflection of the crane girder and drift of the building perpendicular to the crane runway but I have yet to come across anything that gives this limit.

 

[jimstructures]

Try the MBMA Design Manual and look in the crane section for longitudinal crane loading. H/400 seems excessively stiff unless the crane is supported on masonry columns.

Jim H

 

[SteelPE]

I used to have one of those manuals.... but not anymore.

 

[Hokie93]

AISC Design Guide 3, second edition (Serviceability Design Considerations for Steel Buildings) gives some treatment to this topic. Refer to Chapter 7 and the Appendix.

 

[DETstru]

Crane's are very dependent on minimal deflection. CISC has a great (free) design guide for steel structures supporting cranes. The CMAA also has an $84 specification (I think #70 or 74) for bridge crane requirements.

I believe H/400 is the right number.

 

[SteelPE]

I have the first edition of DG 3 and I never would have thought to look in there. I was looking in DG 7. So It appears as if H/100 is allowed..... but I think I am going to be slightly more strict than that.... especially since they said movement of the frames could be observed during operation.