Structural Concrete - Hassoun

208 Chapter 5 Shear and Diagonal Tension
46.13
20.25
47
25.88
12.94
69
82
Figure 5.12 Example 5.2.
4. Calculate V s = (V u − φV c )/φ = (69.83 − 25.88)/0.75 = 58.6 K. Because V s is less than V c1
=
(4 √ f ′ c )b w d,thenS max = d∕2 must be considered (or refer to Fig. 5.10 or Table 5.1: V s < 52.8K).
5. Design of stirrups: Choose no. 3 U-stirrups, A v = 2(0.11) =0.22 in. 2 Calculate S 1 based on V s =
58.6K, S 1 = A v f y d∕V s = 13.2d∕V s = 5.07 in., say, 5 in. (or get s∕d = 0.225 from Table 5.2 or
Fig. 5.10).
6. Calculate maximum spacings: S 2 = d∕2 = 22.5∕2 = 11.25 in., say, 11.0 in.; S 3 = A v f yt ∕50b w =
0.22(60, 000)∕50(14) =18.9 in. (or use Table 5.1); S 4 = 24 in.; S max = 11-in. controls.
7. Because S 1 = 5in.