Civil Engineering Reference
In-Depth Information
Depth Required for Two-Way or Punching Shear (Figure 12.10)
b
o
(4)(35.5)
142 in
V
u
2
(81.0
2.96
2
)(6.12)
442.09 k
442,090
(0.75)(4
d
3000)(142)
18.95 in.
19.5 in.
OK
442,090
d
40
d
142
0.75
2
(
3000)(142)
Solving quadratic
d
13.23 in.
19.50 in.
OK
Depth Required for One-Way Shear (Figure 12.11)
V
u
1
(9.00)(2.208)(6.12)
121.62 k
121,620
(0.75)(2
d
3000)(108)
13.71 in.
19.5 in.
OK
Use 24 in. total depth
3.83
2
M
u
(3.83)(9.00)(6.12)
404 ft- k
M
u
(12)(404,000)
(0.9)(108)(19.5)
2
131.2 psi,
min
for flexure
bd
2
200
60,000
0.0033
k
Use
larger of
or
3
3000
60,000
0.00274
A
s
(0.0033)(108)(19.5)
6.95 in.
2
Use 9 #8 bars in both directions (7.07 in.
2
)
Figure 12.10
Figure 12.11
