Civil Engineering Reference
In-Depth Information
F
i g u r e
7.19 Transfer wall forces.
a computer analysis. The shear wall could be modeled using members stiff enough to
prevent a contribution to deflection due to elongation or flexure of the members.
It is necessary to resolve the forces applied to the transfer wall as shown in Fig. 7.19.
The diaphragm chord forces (horizontal force component previously calculated) at grid
lines 2 and 3 are broken down into vertical, horizontal, and resultant force components as
shown in the figure. The unit diaphragm shears at the transfer wall are shown in the plan
view in the figure. The vertical and horizontal components of the resultant shears applied
along the wall from the roof diaphragm are also shown in the figure and are equal to
(.
51 4
+
104 512
2
.)()
V
H
=
=
0 935 khorizontalcomponent
.
(.
0 935 3
12
)( )
V
V
=
=
0 234 kverticalcomponent
.
The resultant component forces are placed at the center of the top plate. Summing
horizontal forces along the upper diaphragm chord, the resulting force at grid line 3 is
(.
51 4
+
104 512
2
.)()
F
3
=
9 696
.
−
=
8 761
.
k
≅
8 768
.
k
OK
8 768
12
.
v
wall
=
=
0 7307
.
klfatareabetween up
perand lowerchords
By adding the shears transferred into the upper chord from the diaphragm and shear
wall, the upper chord force will close to zero at grid line 3.
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