Design Examples of Steel and Steel-Concrete Composite Bridges - Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges - page 362

The bearing is also subjected to a lateral force from the braking forces of
moving traffic as well as subjected to a longitudinal force from the reactions
of the lower wind bracings, which cause moments around longitudinal and
lateral directions of the bearing base, respectively. Similar to the roller bear-
ing, the material of construction for the bearings is cast iron steel (ISO 3755)
340-550 having a yield stress of 340 MPa and an ultimate stress of 550 MPa.
It should be noted that the overall height of the hinged bearing must be
exactly the same as that of the roller bearing. The general layout and assumed
dimensions of the hinged line rocker bearing are shown in Figure 4.125 . The
braking Q lk forces can be calculated as follows.
Q lbk ¼ 360+2.7 48 ¼ 489.6 (see Figure 4.124 for the direction of
the forces). Also, the reactions from the lower wind bracings ( R tot ) (see
Figure 4.124 for the direction of the forces) were previously calculated as
follows:

9kN
We can now determine the normal stress distribution due to the applied
loads, shown in Figure 4.124 , on the concrete foundation as follows:

R tot ¼ 212 :

M y
I y x

N
A

M x
I x y

f ¼

N
A ¼

2193 36 10 3

950 1100 ¼ 2

:

: 098MPa

9 10 3

M x
I x y ¼

212 190

950 1100 3

:

550 ¼ 0

:

21MPa

= 12

6 10 3

M y
I y x ¼

489 190

1100 950 3

:

475 ¼ 0 : 56MPa

=

12

f max ¼ 2 : 098 0 : 21 0 : 56 ¼ 2 : 87MPa

4

4
5

13.5

10
4 5.5

Figure 4.125 The designed roller and hinged line rocker fabricated steel bearings.