Cable-stayed bridges - Computational Analysis and Design of Bridge Structures - page 363

−68600 −59200

−9000

6600

−172800

98200

Figure 11.31 Moment distribution (kN-m) of one preferred ideal state after superimposed.

0

−31

−28

−28

−2
−2

−23

1

−19 −24

−15 −13

−18

−19 −18

−18 −18 −15

−18

2 5 3

4

4

8

10 8 8

12

13 11

9

14 12

18

23

Figure 11.32 Live load stress envelope (on the top of the girder and side-span side of
tower, MPa).

Table 11.2 Live load extreme displacements (mm)
Position Linear a Nonlinear b
Girder (in the middle of main span) 1081 935
Top of pylon 263 242
a Computed by direct influence line loading, which is obtained by the application of
unit forces while initial stress and sag is considered.
b Obtained by reanalyzing extreme live loads of load case a with consideration of
initial stress, cable sag, and large displacements.

nonlinear effects. The nonlinear analysis of live loads shows that initial
stresses accumulated along the flat arch-like girder will increase the girder
stiffness if large displacement is considered.
The wind pressure is designated by the bridge site and varies at different
altitudes along the towers. With regard to longitudinal connections
between the girder and towers, three alternatives are studied. The first, the
recommended one, is that the girder is restrained with one tower only. The
second is not to restrain at all; the third is to restrain with two towers.