Civil Engineering Reference
In-Depth Information
700 mm
350 mm
Figure 5.19
M
n
1225
0.9
SOLUTION
1361 kN
m
max
if singly reinforced
0.0135 from Appendix Table B.7
A
s
1
(0.0135)(350)(700)
3307 mm
2
M
u
1
bd
2
4.769 from Appendix Table B.8
(4.769)(0.9)(350)(700)
2
10
6
M
u
1
(
bd
2
)(4.769)
736.1 kN
m
M
n
1
736.1
0.9
818 kN
m
M
n
of
1361 kN
m
double reinf. required
M
n
2
M
n
M
n
1
1361
818
543 kN
m
Checking to See if Compression Steel Yields
(3307)(420)
(0.85)(21)(350)
222.32 mm
a
c
222.32
0.85
261.55 mm
261.55
70
261.55
s
(0.003)
0.00220
420
200 000
0.002 10
compression steel yields
M
n
2
f
y
(
d
d
)
10
6
(700
70)(420)
2052 mm
2
543
s
reqd
A
use 3 #32 bars (2457 mm
2
)
A
s
A
s
1
A
s
2
3307
2052
5359 mm
2
use 6 #36 bars (
A
s
6036 mm
2
)
