Design of square footing for a single column - Reinforced Concrete with FRP Bars: Mechanics and Design - page 371

The total area of concrete resisting two-way shear is

A c ′ := 2·(b 1 ′ + b 2 ′)c v ′ = 1530·in. 2

The property of the assumed critical section analogous to the polar
moment of inertia is

3 3 2

cb
6

⋅

+ cb
6

⋅

+ cbb
2

⋅ ⋅

v ′ 1 ′ v ′ 1 ′ v ′ 1 ′ 2 ′

4

J: = = 465757 in ⋅ c

′

Load combination 1:

v: V
A

γ⋅ Mb

2J

⋅

u_ps1 ′ v ′ u_ps1 ′ 1 ′

= + =161.4psi ⋅

u1 ′

c ′ c ′

Load combination 2:

v: V
A

γ⋅ Mb

2J

⋅

u_ps2 ′ v ′ u_ps2 ′ 1 ′

= + = 251.7psi ⋅ u2 ′

c ′ c ′

Load combination 3:

V
A

γ⋅ Mb

2J

⋅

u_ps3 ′ v ′ u_ps3 ′ 1 ′

v: = + = 207.6psi ⋅

u3

′

c ′ c ′

( )

“OK” if maxv ,v ,v ≤φ ⋅ 4fpsi ′ ⋅

u1 ′ u2 ′ u3 ′ v c

′ =

CheckPunchingShear:

“Not good”otherwise

CheckPunchingShear′ = “Not good”

Because the check for punching shear is not verified, the depth of the
footing is increased. The new depth, h, is considered:

h := 30 in.

The following reinforcement depth is computed based on a 4.5 in. con-
crete cover:

d := 25.5 in.

The preceding calculations are repeated.