Floor Loading?

[SteelPE]

I have a project that is a single story metal building with a garage buried underneath. The client is going rent the building out to companies and expects to be storing landscaping equipment on the suspended slab. Making matters worse, the client would like to be able to add a “prefabricated” mezzanine to the suspended floor in the future which will be used for storage.

The only information I have been able to get out of him with regards to the equipment is that he thinks the heaviest tractor that will be supported is 18 kips. He has been able to give me no information with regards to the mezzanine.

We plan on using precast plank with a 2” concrete topping. I need to relay the loading information to the plank company so they can properly design the plank. I am thinking about specifying a H20-44 loading on the plank to cover the possibility of the 18 kip tractor (seems a bit harsh). However, I do not know how to handle the mezzanine loading on the slab. I was thinking about roughing out a column loading and then having the precast company design their planks for this column load at each end but I am not sure if this is correct.

Any guidance with this would be appreciated. The code used is IBC 2009.

 

[frv]

Can you show a "future mezzanine" on the plan, list the loads and ask the plank fabricators to design for that condition?

The owner needs to tell you where he anticipates the mezzanine footprint. To allow for flexibility, you could assume the mezzanine will be light storage, although that is asking a lot of a suspended slab.

 

[Den32]

Agree with FRV: On structural drawings, I would show the (future) extents of the mezzanine as well as the design dead and live loads (in PSF). Also, show the column concentrated loads and locations on the planks for the plank manufacturer to design.

Think of it this way: 10 years from now another Structural Engineer will be designing this new mezzanine - what information will be needed......plus what will CYA


Also, think about how the base plate will be installed into the planks.....don't want to be drilling through strands. May want to note it.


Will also have to handle mezzanine lateral loads (seismic) per IBC 2009

 

[SteelPE]

Thanks guys, I guess I will proceed as planned an not the allowable spacing and location of the mezzanine columns with the required maximum load on the drawings. I guess this is the best way to handle the situation.

Lateral loads are not a concern as the plank would be resting on a CIP foundation system.

 

[a2mfk]

With your specific situation, the point loads, the unknowns, I would lean towards a composite deck and slab or CIP slab system that gives you a bit more flexibility then hollow core panels.

 

[hokie66]

Agree with a2mfk. A cast in place slab is the way to go. But for the mezzanine, you need to do enough design/analysis to locate columns and their loading, and show these clearly on your drawings. Otherwise, the client will be disappointed at a future date, and will come looking for you.

 

[frv]

a2mfk brings up a very valid point. CIP or composite will definitely give you more flexibility.

What will the precast planks be resting on? If CIP or precast beams, then you may be able to simply lay out the beams so that the mezzanine columns would fall on the beams. It is much easier to design the beams for a large point load than a precast plank (especially hollowcore).