Design of square footing for a single column - Reinforced Concrete with FRP Bars: Mechanics and Design - page 370

The portion of this moment transferred by the eccentricity of the shear
force, γ v M u , can be calculated as follows. This moment creates additional
shear on the surface of the critical section for punching shear:

1

γ= : =0.6

f ′

1+ 2
3

b
b

1 ′

⋅

2 ′

γ v ′:= 1 - γ f ′ = 0.4

γ v ′ ·M u_ps1′ = 17.1·kip·ft

The same can be repeated for the other two load combinations:
Load combination 2:

( )

2

bbb
b

−⋅

12
2

′ ′

V_ :P =⋅ = 372.9kip ⋅ ups2 ′ u2

4

3

b
12

bb
4

⋅

′ 2 ′

−

M_ :M =⋅ = 36.6kip ft ⋅ ⋅

ups2' u2

4

b
12

γ v ′·M u _ ps2′ = 14.6·kip·ft

Load combination 3:

( )

2

bbb
b

−⋅

12
2

′ ′

V_ := P ⋅ = 258.9kip ⋅

ups3 ′ u3

4

3

b
12

bb
4

⋅

′ 2 ′

−

M_ :M =⋅ = 175.3kip ft ⋅ ⋅

ups3 ′ u3

4

b
12

γ v′ ·M u _ps3′ = 70.13·kpi⋅ft

The maximum punching shear stress v u is to be computed.
The depth of the concrete that resists shear is computed as

c = 5

′

2 kd=9 in

⋅ ⋅ .

v