Design Examples of Steel and Steel-Concrete Composite Bridges - Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges - page 401

The radius of the curved part of the upper bearing plate, which has a
length of 600 mm as shown in Figure 4.159 , 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

R D+L+ F
600 ¼

3,132,800
600 ¼ 5221

N

Sd ¼

: 3N = mm

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

N Rd as follows:

131 R
Then, R¼ 157.6 mm, taken as 160 mm.

5221 : 3 ¼ 33 :

Design of Lower Bearing Plate
The lower bearing plate is shown in Figure 4.159 . 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:

8 10 3
600 800 ¼ 6

R D+L+ F
a 3 b 3 ¼

3132 : f c

g c ¼

40
1

f c ¼ : 53MPa <

5 ¼ 26

: 7MPa

:

f c
g c ¼

40
1

5 ¼ 26

: 7 (for a typical concrete in bridges of C40/50 with f ck )

:

The plate thickness t 3 can be calculated from the distribution of bending
moment, caused by the pressure on the concrete foundation, as follows:
M¼ 105, 786Nmm per unit width of the plate:

b 3 t 3 1 t 3

25 t 2 mm 3

W pl ¼

4 ¼ 4 ¼ 0

:

M
W pl ¼

f y
g M0

105,786
0

340
1 25 t 3 ¼ 0

Then, t 3 ¼ 35.3 mm, taken as 40 mm, as shown in Figure 4.159 .

: :

4.5.14 Design of Hinged Line Rocker Steel Fabricated Bearings
Finally, we can now design the hinged line rocker steel fabricated bearings
shown in Figure 4.126 and detailed in Figure 4.160 . The maximum vertical