Podium Slab Design

[DC_Engr]

Hi All
Working on a podium job that’s in SDC B. The overall building design is by EOR and our contract is limited to sizing the gravity members including gravity columns at the podium/transfer lever for loads shown on EOR’s structural plans. Interestingly, they have lots of wood walls, bearing on podium slabs and beam, labeled shear walls. However, only gravity loading is called for these walls so no shear or overturning due to seismic or wind is specified on plans. However, at each end of these wood shear walls the drawings require a 10,000lbs hold-down/connections for uplift/bearing loads to be designed by ‘podium engineer’. Would you treat this requirement to apply only to the connection or you would include this seemingly arbitrary 10kip bearing/uplift load in slab/beams design? Note that Some of the member sizes called out in EOR drawings are such that they will need to be made deeper to make things work, so obviously this 10k load will drive up the demand. However, the question is should that connection load demand even be part of member design regardless of its impact to member sizes?

 

[KootK]

However, the question is should that connection load demand even be part of member design regardless of its impact to member sizes?

Yes, it should. That load has got to make its way to the ground somehow, right?

I don't envy you this task. What a nightmare of a delegated design assignment. EOR's take all kinds of shortcuts and simplifications when they design podium slabs themselves. It will be quite the challenge for the EOR to communicate all of that to you such that you can execute the design successfully.

The uplift loads are probably the most critical thing because the connection detailing for that is a bear. That said, for every uplift load, there is a downward load causing punching that needs to be made to work. And, yeah, all of that theoretically needs to make it to the foundation. At some point, these loads get small relative to the total load going to primary members such that they can probably be ignored. You'll need to coordinate with the EOR for that to figure out where the cutoff is etc.

I've done plenty of precast podium work where the EOR's just forced me to consider the worst of all possible cases with minimal direction. In their world, that feels as though it makes sense for expedience and liability. It can make for an ugly podium design however.

 

[Aesur]

I'm assuming you didn't like the responses in your last post of this exact question or it was deleted for some other reason last week? I suggest you ask the EOR instead of people on this forum.