Wood Shear Wall Problem

[courtnvm]

I have an interesting problem to figure out. I have essentially a 40' x 80' two-story wood structure. This structure is a church, which has a lot of windows. On the south side of the structure there are many openings. The main roof has a 12:12 roof slope. There are three dormers on the north and south side of the structure. These dormers contain an aluminum frame for a stained-glass window.

My problem is that the windows prevent me from having a collector/strut for my wood shear walls. Are there any suggestions on how to do my shearwalls. Could I just have one segmented shear wall at the end of the building?

All suggestions are welcome.

Thank you for your time and attention.

Val Courtney, PE
Optimal Engineering, Inc.

 

[NKT]

Consider creating a load path around the windows:

·Vertical beams at the sides of the window.
·Straps from collector to beam.
·Straps at the top and bottom to transfer tension past the window.

Make sure to look at beam deflections under the chord/collector loads, especially if you have very tall windows.

Hope this helps,
NKT

 

[courtnvm]

NKT--

Thanks for the suggestion.

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This is the typical layout of my dormers. So if I understand you correctly I could put a vertical beam on each side of the window and a horizontal beam at the bottom of the window to collect my wind/seismic force to the other side of the window. Also, if I could collect my force around the window then I could analyze the whole south side as a perforated shear wall. Please let me know if my thought process is correct.



Val Courtney, PE
Optimal Engineering, Inc.

 

[NKT]

Val:

I think you interpreted my post correctly...

Make sure to pay attention to the top of the window too; the collector/chord force is split around the window in the situation you've shown above. For design purposes, the vertical beam on each side of the window is a simply-supported beam with a point load between the supports; you have to provide a load path for both reactions.

There could be other ways of going about this, depending on the geometry. One may be to create a collector further up the roof, if the dormers come in low enough on the roof to leave the diaphragm with an acceptable aspect ratio. I strongly prefer to transfer the loads around the window as I described above because it is a simple and direct load path.

Based on the limited information provided, this doesn't look like a perforated shearwall application. Once you create a continuous collector, you have a simple dipahragm->collector->shearwall system.

-NKT