Design Examples of Steel and Steel-Concrete Composite Bridges - Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges - page 450

Assuming that the thickness of the sole plate is t 1 , with detailed dimen-
sions shown in Figure 4.209 based on the lower chord member L 1 dimen-
sions, we can determine the maximummoment applied to the sole plate ( M )
as follows:

e
2 ¼ 4433

48 5

2 ¼ 107,522,075Nmm

:

9 10 3 M ¼R D+L+ F : :

Section plastic modulus ( W pl ) ¼b 1 t 2 /4 ¼ 700 t 2 /4 ¼ 175 t 2
The plate thickness t 1 can be calculated now as follows:
M
W pl ¼

f y
g M0
107,522,075
175 t 1

340
1

¼

0
Then, t 1 ¼ 42.5 mm, taken as 50 mm, as shown in Figure 4.209 .

:

Design of the Rollers
The design of rollers requires determination of the diameter, length, and
number of rollers to resist the vertical load as well as the arrangement and
allowed movement in the direction of rollers. The design axial force per unit
length of roller contact N Sd

specified in BS EN 1337-1 [3.11] shall satisfy

N

Sd N Rd

where N Rd is the design value of resistance per unit length of roller contact,

which is calculated as

f u 550 2

210,000

1
g 2 m ¼ 23 R

1
1 ¼ 33

N

Rd ¼ 23 R

E d

: 131 R

Assume the number of rollers is 2 and their length is 800 mm as shown in
Figure 4.33 :

9 10 3
1600

R D+L+ F
2 800 ¼

4433 :

N

Sd ¼

¼ 2771 : 2N = mm

Then, the radius of rollers can be determined by equalizing N Sd with

N Rd as follows:

131 R
Then, R¼ 83.6 mm, taken as 85 mm and the diameter D is 170 mm.

2771 : 2 ¼ 33 :