Formwork for Concrete Structures by R.L.Peurifoy and G.D- By EasyEngineering.net

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Forms for Columns 297
B
y
A
A
x
B
x
z
w
x
x
wx
y
y
wx
FIGURE 10-5 Column forms with wood yokes.
A
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in position. The members are designed as side yokes (A) and end
yokes (B). The members must be strong enough to resist the forces
transmitted to them from the concrete through the sheathing.
End yoke B is held against the sheathing by two hardwood
wedges, which act as end supports for a simple beam subjected to a
uniform load. Consider the two wedges to be x in. apart, producing a
span equal to x. Let the spacing of the yokes be equal to l in. Let P
equal the pressure on the sheathing in pounds per square foot. The
uniform load on the yoke will then be:
w = Pl/12 lb per lin ft
The bending moment at the center of the yoke will be:
The resisting moment will be:
M = wx 2 /96 in.-lb
= (Pl/12)(x) 2 /96
= Plx 2 /1,152 (a)
M = F b
S
(b)
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