Seismic loading for freestanding wall

[StuSE]

Hey you guys;

It would appear that the seismic loading for freestanding walls on spread footings is aquired under "non Structural components" in the 2006 IBC. For this situation, how does z/h work?

Thanks,
Stu

 

[sandman21]

Take the average ht. of the wall apply as uniform load on wall.

 

[wannabeSE]

Since the height at point of attachment, z = 0, I have used z/h = 0

 

[JAE]

I would agree with z = 0 ....the point of attachment.

 

[vandede427]

could you please help me find this in IBC 2006. are you sure you didn't mean ASCE7?

 

[StuSE]

Yes, you are correct vande, it is ASCE7-05. From another thread, I gathered that the formula for non-structural components was more for parts at different levels of a building.

So next I would tend to think this is a Non Building structure (Fp = 0.3SdsW). However, the formaula given for 'rigid structures' is for a structure with a period of 0.06s or less. A freestanding wall it liable to have a larger period than that.

I am ending up using the formula in section 12.11 for structural walls(Fp = 0.4SdsW). I would like to use the Nonstructural Components (Sect 13) with z = 0 which puts me back down to the minimum of Fp =0.3SdsW. The assertion of letting z=0 works for calculating the steel for attatching the wall to the foundation. For determining the forces for overturning and sliding of the monolithic element, I am unsure about letting z = 0.

I discussed this with the reviewer of the project and of course he was comfortable with the conservative value.

Thanks you guys, for your feedback. I have been picking up good information from this board.

 

[vandede427]

I would argue that a cantilevered firewall should NOT be categorized as a non-structural component.