Structural Analysis and Design of Steel Railway Bridges - Design of Modern Steel Railway Bridges - page 180

5.2.1.3.1 Maximum Shear Force in Simply Supported Spans [with
Concentrated Moving Loads Applied Directly to the
Superstructure ( Figure 5.18) ]
Equating maximum shear force, V C , from Equation 5.1 with the shear force, V Ce ,at
location C from an equivalent uniform load, w ev , yields

− P L 2 L
(L

.

P T x T
L

w ev = (5.23)

−

a) 2

Equation 5.23 can be plotted for different P T and P L (which are dependent on load
configuration and span length) at locations C on the span. Figure 5.19 shows the
equivalent uniform load for shear force at the end, 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.

5.2.1.3.2 Maximum Shear Force in Simply Supported Spans [with
Concentrated Moving Loads Applied to the Superstructure
by Transverse Members (Figure 5.20)]
The location in the panel BC where the shear due to an equivalent uniform load,
V BCe =

0, is

(L − a)s p
L

−

(L a)

= =

d

1 ,

(5.24)

− s p n p −

where n p = L/s p is the number of equal length panels.

P T

P L

P n

C

A

B

b n x T

a

L /2 L /2

w e

V Ce

FIGURE 5.18 Equivalent uniform load for shear force for concentrated moving loads applied
directly to the superstructure.