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Concrete/Masonry Partition Walls

EngineerRam

Structural
Jul 31, 2014
52
Hello,

I am designing some concrete and masonry partition walls in accordance with Chapter 13 of ASCE 7-05 (non-structural components). The walls are clipped at the top soffit in order to restrain out-of-plane translation, but not to provide in-plane resistance. Assuming pinned-pinned supports, I am not encountering issues with the anchorage of the walls for out of plane action. However, if I were to use the same ASCE section for in-plane action, the walls act as cantilevered walls as the walls are only restrained for out of plane action. The resulting seismic load for anchorage of in-plane action is quite large (over 200% of the self weight). I am inclined to just detail the walls as special shear walls and utilize a much lower Cs value (0.569). This however, does not account for the walls being anchored at elevations over SOG level. What are everyone's thoughts on this approach?
 
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I know you’re designing to an older code, but take a look at what TMS 402/602-2022 has to say, with the benefit of additional research.

Traditionally, the options were to either isolate the non-participating wall (which you have) or treat it like a shear wall (which you are considering). There’s a new exception, as follows:

1738584974908.png

This might work for your situation, if you can justify it to the AHJ. So pin it at the top and check the deformation compatibility. Worth noting that Bennett generally discourages use of this exception.
 
Last edited:
..The walls are clipped at the top soffit in order to restrain out-of-plane translation, but not to provide in-plane resistance.
That is fine. The partitions in general assumed to span out-of-plane between diaphragms and , their displacements and accelerations are affected by two diaphragms that may have different response.
The resulting seismic load for anchorage of in-plane action is quite large (over 200% of the self weight). I am inclined to just detail the walls as special shear walls and utilize a much lower Cs value (0.569). This however, does not account for the walls being anchored at elevations over SOG level. What are everyone's thoughts on this approach?
I do not have any idea that how you did calculate the in-plane seismic effects but i would consider only the out-of-plane design and reinforced masonry for high seismic zones. I would also like to remind the exceptions stated at 13.5.8.1.

The following doc . gives insight for the subject.
 

Attachments

  • NIST.GCR.18-917-43 Recommendations for Improved Seismic Performance of Nonstructural Components.pdf
    13 MB · Views: 2
Hello,

I am designing some concrete and masonry partition walls in accordance with Chapter 13 of ASCE 7-05 (non-structural components). The walls are clipped at the top soffit in order to restrain out-of-plane translation, but not to provide in-plane resistance. Assuming pinned-pinned supports, I am not encountering issues with the anchorage of the walls for out of plane action. However, if I were to use the same ASCE section for in-plane action, the walls act as cantilevered walls as the walls are only restrained for out of plane action. The resulting seismic load for anchorage of in-plane action is quite large (over 200% of the self weight). I am inclined to just detail the walls as special shear walls and utilize a much lower Cs value (0.569). This however, does not account for the walls being anchored at elevations over SOG level. What are everyone's thoughts on this approach?
I've always just isolated them for in-plane by providing horizontally slotted connections. I wouldn't think much more about it. I am more interested in what state is still under 7-05.
 

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