Civil Engineering Reference
In-Depth Information
Equivalent uniform load for Cooper's E80 wheel
load (1/2 of axle load) for moment
12,000
1/4 point moment
Center moment
11,000
10,000
9000
8000
7000
6000
5000
4000
0 10 20 30 40 50 60 70
Span length (ft)
80 90 100 110 120 130 140 150
FIGURE 5.22
Equivalent uniform load for bending moment for a Cooper's E80 series of
concentrated moving wheel loads applied directly to the superstructure.
w
em
, yields
2
(P
T
(x
T
/L)a
−
P
L
x
L
)
w
em
=
.
(5.26)
a(L
−
a)
Equation 5.26 can be plotted for different
P
T
and
P
L
at locations C on the span.
Figure 5.22 shows the equivalent uniform load for bending moment at the 1/4 point
and the center of the span for a Cooper's E80 series of concentrated moving wheel
loads applied directly to the superstructure.
5.2.1.3.4 Maximum Bending Moment in Simply Supported Spans [with
Concentrated Moving Loads Applied At Panel Points to the
Superstructure
(Figure 5.23)]
Equating the maximum bending moment,
M
BC
, from Equation 5.9 with the bending
moment,
M
BCe
=
w
e
s
p
(s
p
+
a)
, in panel BC from an equivalent uniform load,
w
em
,
yields
(P
T
(x
T
/L)) a
(P
BC
) (c/s
p
)d
−
(P
L
)b
−
w
em
=
.
(5.27)
s
p
(s
p
+
a)
Equation 5.27 can be plotted for different
P
T
and
P
L
and
P
BC
for various panels
on the span. For a specific design load such as Cooper's configuration the value of
(P
T
(x
T
/L)) a
(P
BC
)(c/s
p
)d
can be calculated for various values of
x
T
and the equivalent uniform load for bending moment can be determined in various
panels along the span. The equivalent uniform load for maximum bending moments
in the panels will have the general form shown in
Figure 5.22.
−
(P
L
)b
−
