Cable-stayed bridges - Computational Analysis and Design of Bridge Structures - page 358

preprocessing tool, modeling a girder in such detail will be simple and fairly
easy. Load distributions, on the other hand, will be more accurate and struc-
tural weight calculations will be simplified. When influence surfaces * are
used in live load analyses, such a grid model will also help to improve the
interpolation of influence values as the interpolation triangles are getting
smaller and more regular.

11.4.2 Pylons
In the transverse direction, shape of a pylon can be in a single solid/hol-
low column H, invert Y, diamond, or other shapes. Figure 11.26 shows
two alternative pylon plans of Sutong Bridge (China). 3D beam elements
are usually used to model pylons. When 2D modeling is used for prelimi-
nary analyses, cross-sectional properties should be calculated carefully

1000

500 1000

A-A

1000

200 600 200

140

A A

B-B

1000

200 600 200

80

B B

C-C

2000/2

200 600 200

800 700 800

2000

C C

(a) (b)

Figure 11.26 (a, b) Two alternative pylon plans of Sutong Bridge.

* Influence surfaces of all deck nodes are built from the results of analyses for a series of unit
vertical loads applied to the deck and stored for later usage for finding the extreme load
effects.