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seismic for non-structural

seismic for non-structural

seismic for non-structural

(OP)
I'm trying to design a metal spiral stair and it said on the specification that is should be design under earthquake load. The question is how should i compute the earthquake load for non structural and how to apply them on the stair?. Upon searching on this matter I found this table
. Should I apply the design force calculated to the whole stairs? for example selfweight x seismic factor for lateral loading? Any opinion will be very much appreciated.

RE: seismic for non-structural

The first place to look is in your local building code. If it is in the USA, the local building code will most likely reference the 2005 or 2010 version of ASCE 7. The structural engineer responsible for the project should be able to assist you.

RE: seismic for non-structural

(OP)
thank you for your response wannabeSE. Im using UBC1997 for the computation of lateral load. The only thing that confuse me is how should i apply the lateral load. should i apply the total lateral load to the centroid of the of the stair or just multiply it selfweight by the seismic factor and apply it to x and z directions?

RE: seismic for non-structural

Jandra -

SEAoC issued a design guide on the 1997 UBC that had an example similar to this.... A non-structural attachment connected to multiple levels. I believe what the design guide tells you to do is calculate different acceleration values for the two levels using that formula and the trib weight for the element at the attachment point. At least that's the way I remember it.

Alternatively, I suppose, you could look a the acceleration for the two levels and interpolate this to come up with an acceleration at the centroid of the mass of the element that's being attached.

RE: seismic for non-structural

I agree with wannabe. It's not appropriate to use UBC 1997.

But you calculate the base shear and distribute the load based on height and mass distribution.

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