FLOOD06430

• County: Statewide
• Basin: Statewide
• Title: Conduits, Culverts and Pipes
• Date: 3/3/1969
• Prepared By: US Army Corps of Engineers
• Floodplain - Doc Type: Educational/Technical/Reference Information

I
I

EM 1110-2-2902
3 Mar 1969

I

When N falls inside the kern, minimum reinforcement only is required and f. is found by the equa-
tion:

I

f, - (N# + 6M"#) F* _________________________________________________________(20)
bD bD'
When N falls outside the kern, the stress in the tension steel is:
f. = (d ; S) nf,F* __ ___ _ __ __ _ ___ _ ___ __ _ __ _ _ __ _ __ __ __ __ ___ _ __ _ __ __ __ __ __ _ (21)

and the stress in the compression steel is:
f'. = C ; d') 2nf.F* -- -- - - - - - - - -- - - - - - - -- -- -- - -- - -- - --- -- --- --- --- - --- - -- -- -- (22)

(4) Ultimate Strength Design Method. In addition to an elastic analysis, critical sections
should be investigated by the ultimate strength design method based on a minimum load factor
of 1.8. The following procedure is suggested:

e = M/N
T = A,f,
C, = A',Jy
Cb = d (87,000) / (87,000 + f,)
ab = k,cb (where k, = 0.85 when f'. = 4000)
C, = 0.85 f',abb (use b = 12")
~ F, = 0 = Pb + T - C, - C.
Pb = C. + C. - T

Find plastic centroid (location of resultant load which would give uniform strain across the
section) .

I

I
I
I

I

I
I
I
I
I

.Apply curved-beam correction factor, F, at inside face only of conduits with curved shells-see paragraph
5b(I).

N

I

e ::M/N j
r Cc rs
I -As
0 I
"l
A'-
5
I

T

I
I
I
I

Fig. ~. Typical Stres8 Diagram-Ultimate Strength Dengn

8