General Information
Figure 1 shows a suspension bridge that is used by motorcycles, bicycles and pedestrians.
| Type | Two-span suspension bridge |
| Main span | ≅ 70 m |
| Deck width | ≅ 2 m |
| Deck width to main span ratio | ≅ 1:35 |
| Shore Pylon | Reinforced concrete (H-shaped) |
| Central Pylon | Steel and reinforced concrete (H-shaped) |
| Girder | Steel transverse beam |
Cross-Section
Figure 2 shows a bottom view of a bridge sector.
Over the girders, which are made of circular hollow profiles, are placed four steel wire ropes (marked by the numbers) and timber stringers. The distance between the stringers is irregular; some are connected to the girders, and some are not. Over the stringers are placed the deck's transverse timber boards, which have a similar cross-section as the stringers.
What are some possible reasons for the above shown stringer arrangement?
Intermediate Main Span Supports
Figure 3 shows a schematic partial lateral view of the bridge.
The first main span sector is also supported by intermediate supports made of timber. The distance between the hanger cables is about constant along the two spans. The main span is about 70 meters, and span A is about 60 meters. Figure 4 shows a main span sector with intermediate supports.
Failed Steel Wires of a Hanger Cable
Figure 5 shows a hanger cable.
The hanger cable passes once over the main cable, and the termination consists of U-bolt clamps. Enlarged view 1 is shown in figure 6.
Failed steel wires at the top outer side of the wire rope are noticeable.
What are the main structrual consequences?
Stay Cables and Additional Girders
Figure 7 shows a schematic lateral view of the central pylon region.
The central pylon region includes four stay cables and six additional girders: the former are anchored at the cable barriers and the pylon; the latter are connected to the cable barriers by short hanger cables. The cable barriers (top cables) are anchored on shores one and two and run horizontally along the two spans. Figure 8 shows the anchorage at the cable barrier of the B stay cables.
The anchorage consists of a direct cable-to-cable connection fixed with U-bolt clamps. Figure 9 shows the anchorage at the pylon.
The stay cables termination consists of U-bolt clamps.
Figure 10 shows additional girder and short hanger cable 1.
