"T" shaped flexible diaphram 1

[tricalcim]

Stratagies are appreciated.

Plan view with north-up(Y-direction)and east-right(X-direction).

Now, draw a horiz gridline labeled "A." Offset a second line 10' North and call it "B." Offset another line from "B" 30' North and label it "C." And, finally, offset from "C" 10' North another line and call it "D."

Now draw a vertical(north-south) gridline labeled "1." Offset this line 50' east and call it 2. Finally, offset 10' east from line 2 and call it "3."

The permiter of the building can now be sketched by connecting the points A1,D1,D2,C2,C3,B3,B2,A2,A1. (It should be a 50' by 60' building with two 10' re-entrant corners.

For East-West: Would you add 2-50' struts (C1-C2 AND B2-B3) and assume that the forces are distributed based on tributary area to lines A,B,C, and D? This would really load walls B2-B3 and C2-C3 (This doesn't seem appropriate strategy).

Or......I guess I could strap and block B2-B3 and C2-C3 for a distance, and yet, not allow these walls to take shear.

appreciate input, thoughts..appolgy for the sketch.

 

[DaveAtkins]

Even though you have a flexible diaphragm, the aspect ratio of the diaphragm is 1:1 and so I would go ahead and distribute the lateral forces to the walls based on relative stiffness (thus assuming the diaphragm is rigid). You will have to create drag strut lines along Grid Lines B and C.

DaveAtkins

 

[tricalcim]

Thanks Dave...It seems that struts at gridlines B and C are what I'm trying to avoid because I do not want to attract load to B2-B3 and C2-C3 because of window glazings, and can't place interior shear walls at B or C either. What I'm stratgizing is to tie B2-B3 and C2-C3 into the main diaphram and use A line and D line to carry the shear.

 

[AlohaBob]

So long as this is the way you detail it, then that's the way it should work. Shearwalls at D and A only. The remainder of the diaphram not tied to vertical stiff elements. So B and C are tied out of plane, but allowed to slide at the diaphram in plane.

I would assume a flexible diaphram first, and later if it's significant, consider affects of a rigid diaphram.