Design Examples of Steel and Steel-Concrete Composite Bridges - Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges - page 321

rollers as well as the allowed movement in the direction of rollers.
The thickness of the upper bearing plate can be determined as follows:

2 10 3
2

R D+L+ F
2

ð D + 100 Þ 5822 : 320

2 ¼ 465,776,000Nmm

M ¼ ¼ :

2

b 2 t 2 800 t 2

4 ¼ 200 t 2 mm 3
The plate thickness t 2 can be calculated now as follows:
M
W pl ¼

W pl ¼

4 ¼

f y
g M0
465,776,000
200 t 1 ¼

340
1

0
Then, t 1 ¼ 82.8 mm, taken as 90 mm, as shown in Figure 4.90 .
The radius of the curved part of the upper bearing plate, which has a
length of 600 mm as shown in Figure 4.90 , can be determined the same
way as that adopted for the design of the rollers:

:

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

2 10 3
600

R D+L+ F 5822 :

N

Sd ¼

600 ¼

¼ 97036 : 7N = mm

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

N Rd as follows:

97,036 : 7 ¼ 33 : 131 R

Then, R¼ 293 mm.

Design of Lower Bearing Plate
The lower bearing plate is shown in Figure 4.90 . The width and length of
the plate are dependent on the strength of concrete and are dependent on the
spacing between rollers and the length of rollers as well as the allowed move-
ment in the direction of rollers. The thickness of the upper bearing plate can
be determined as follows:

2 10 3
600 800 ¼ 9

R D+L+ F
a 3 b 3 ¼

5822 : f c

g c ¼

40
1

f c ¼ : 1MPa <

: 5

¼ 26 : 7MPa for a typical concrete in bridges of C40 ð = 50 with f ck Þ