General Information
Figure 1 shows a cable-stayed bridge that is used by motorcycles, bicycles and pedestrians.
![Cable-stayed bridge over a river](bridges/cable-stayed-bridges/bridge-8/1-cable-stayed-bridge.jpg)
Type | Single-span cable-stayed bridge |
Main span | ≅ 27 m |
Deck width | ≅ 1.5 m |
Girder | Steel twin C-girder (cold formed) |
Pylon | Reinforced concrete and steel (portal shaped) |
Stay cable arrangement | Radial (two cable planes) |
Arrangement of Stay Cables
Figure 2 shows a schematic partial three-dimensional view of the bridge.
![Three-dimensional drawing of a cable-stayed bridge](bridges/cable-stayed-bridges/bridge-8/2-3d-view.jpg)
There are a total of 24 stay cables: 20 front and 4 back stay cables. Stay cables 5 and 6 are anchored to the C-girder at the same position, as shown in figure 3.
![Arrangement of stay cables in the mid-span region](bridges/cable-stayed-bridges/bridge-8/3-stays-mid-span.jpg)
What is another possible arrangement?
Stay Cables Anchorages
Figure 4 shows a stay cable to C-girder anchorage.
![Anchorage at the girder](bridges/cable-stayed-bridges/bridge-8/4-stay-anchorage.jpg)
The stay cables are anchored at the C-girder by a turnbuckle and a multi-bent rebar. The C-girder has a hole in the web region through which the multi-bent rebar passes. Figure 5 shows an anchorage viewed from above.
![Anchorage at the girder](bridges/cable-stayed-bridges/bridge-8/5-stay-anchorage.jpg)
Figure 6 shows a further anchorage viewed from above.
![Anchorage at the girder](bridges/cable-stayed-bridges/bridge-8/6-stay-anchorage.jpg)
The multi-bent rebar has a different shape than the multi-bent rebar in figure 5.
The stay cables are anchored to the pylon as shown in figure 7.
![Anchorage at the pylon](bridges/cable-stayed-bridges/bridge-8/7-stay-anchorage.jpg)
The stay cables are anchored at the pylon top by a single embedded U-bar; the front stays are stacked one on top of the other. Figure 8 shows a schematic partial-cross section of the pylon top region.
![Pylon top cross section of a cable stayed bridge](bridges/cable-stayed-bridges/bridge-8/8-pylon-top.jpg)
Wire Rope Termination
Figure 9 shows a stay cable end in the main span region.
![Wire rope termination using cable clips](bridges/cable-stayed-bridges/bridge-8/9-end-fitting.jpg)
Each stay cable is made of a steel wire rope, and the termination consists of U-bolt clamps. The U-parts are on the live end of the wire rope, and there is no wire rope thimble between the turnbuckle and the wire rope. Each front stay cable has three U-bolt clamps: two are used for the girder anchorage, and one is used for the pylon anchorage, as shown in figure 10.
![Wire rope termination using cable clips](bridges/cable-stayed-bridges/bridge-8/10-end-fitting.jpg)
Stay Cable Vibration
Figure 11 shows the bridge viewed from the mid-span region.
![Mid-span region of a cable-stayed bridge](bridges/cable-stayed-bridges/bridge-8/11-main-span.jpg)
The stay cables are sagging. Video 1 shows stay cable 5 during hand-induced vibration.
Suspended Bridge
A suspended bridge as an alternative variant and the used cable-stayed bridge are shown in figure 12.
![Three-dimensional drawings of a cable-stayed bridge and a suspended bridge](bridges/cable-stayed-bridges/bridge-8/12-3d-view.jpg)
What are some possible reasons for choosing the above shown cable-stayed bridge instead of a suspended bridge?