Civil Engineering Reference
In-Depth Information
Checking Shearing Strength at a Distance 22 in. from Face of Wall
V
u
for 12 in. width of footing
22
12
2.25
(4.36)
1.82 k
f
c
bh
(0.55)
4
3
4
3
V
u
(
3000)(12)(22)
10,604 lb
10.60 k
2.05 k
OK
Use 24
footing
12.15 SI EXAMPLE
EXAMPLE 12.11
Design a reinforced concrete wall footing to support a 300-mm-wide reinforced concrete wall with
a dead load
D
300 kN/m
2
and a live load
L
200 kN/m
2
. The bottom of the footing is to be 1 m
below the final grade, the soil weight is 16 kN/m
3
, the concrete weight is 24 kN/m
3
, the allowable
soil pressure
q
u
is 190 MPa/m
2
,
f
y
420 MPa, and
c
f
24 MPa.
SOLUTION
Assume 450-mm-Deep Footing (
d
360 mm)
450
1000
550
1000
(16)
170.4 kN/m
2
q
e
190
(24)
300
200
170.4
width required
2.93 m
Say 3.00 m
Bearing Pressure for Strength Design
q
u
(1.2)(300)
(1.6)(200)
3.00
226.7 kN/m
2
Depth Required for Shear at a Distance
d
from Face of Wall (See Figure 12.26)
3.00
2
150
1000
360
V
u
(226.7)
224.4 kN
1000
6
V
u
(0.75)(
f
(6)(224
.4)
(10)
3
(0.75)(
24)(1000)
366 mm
360 mm
d
c
)(
b
w
)
But OK
300 mm
wall
q
u
= 226.7 kN/m
2
0.300 m
1.350 m
1.350 m
3.00 m
Figure 12.26
