General Information
Figure 1 shows a suspension bridge that is used by motorcycles, bicycles and pedestrians.
Type | Single-span suspension bridge |
Main span | ≅ 70 m |
Deck width | ≅ 1.5 m |
Deck width to main span ratio | ≅ 1:46 |
Pylon | Reinforced concrete |
Girder | Timber transverse beam |
Hanger Cable to Timber Girder Connection
Figure 2 shows a schematic cross-section of the bridge.
A single hanger cable runs from main cable 1 to main cable 2 via the girder bottom side. The hanger cable passes through the girder through two vertical holes. The forces are transferred by direct (cable to girder) contact. Figure 3 shows a hanger cable to girder connection viewed from below.
There is an offset between the vertical hole and the hanger cable bent region, and a longitudinal crack that extends from the girder's end to the hanger cable bent region is noticeable. The timber fiber direction is indicated by the double white arrow. A further connection viewed from the side is shown in figure 4.
A similar crack configuration and hanger cable offset are noticeable; a stringer and a deck plank are touched by the hanger cable.
What are the main consequences?
Figure 5 shows a further hanger cable to girder connection.
An additional cable is connected to the hanger cable (over the deck region) by U-bolt clamps, bent around the girder, and fixed with two U-bolt clamps. Free space between the additional cable and the girder is noticeable.
Hanger Cables
Figure 6 shows a main span sector.
Noticeable are taut, slack, and twisted hanger cables, irregular spacing, different numbers of U-bolt clamps, and different main cable connections (e.g., with and without a frame plate).
Deck Deformation
Figure 7 shows a main span sector.
Deck deformation is noticeable.