General Information
Figure 1 shows a pedestrian suspension bridge.
![Pedestrian suspension bridge over a river](bridges/suspension-bridges/bridge-17/1-pedestrian-suspension-bridge.jpg)
Type | Single-span suspension bridge |
Main span | ≅ 35 m |
Deck width | ≅ 2 m |
Deck width to main span ratio | ≅ 1:17 |
Pylon | Reinforced concrete (tower square shaped) |
Girder | Steel arch truss |
Steel Arch Truss
Figure 2 shows a schematic lateral view of the bridge.
![Schematic lateral view of a pedestrian suspension bridge](bridges/suspension-bridges/bridge-17/2-lateral-view.jpg)
The arch rise r ≅ 2 m, and the main span s ≅ 35 m; that gives an arch rise to main span ratio of about 1/17. Figure 3 shows an arch truss sector.
![Arch truss of a pedestrian suspension bridge](bridges/suspension-bridges/bridge-17/3-arch-truss.jpg)
The truss height h ≅ 0.4 m, and the truss members consist of rectangular hollow profiles. Assuming a two-hinged arch truss with a dead load of 100 kg/m. Figure 4 shows a schematic lateral view of the bridge without the suspension system.
![Lateral view of a steel arch truss bridge](bridges/suspension-bridges/bridge-17/4-lateral-view.jpg)
Gusset Plates
Figure 5 shows an arch truss sector.
![Gusset plates of a steel arch truss](bridges/suspension-bridges/bridge-17/5-arch-truss.jpg)
The gusset plates (marked by the letter G) are welded on each upper chord node and alternating on the bottom chord nodes.
Are the gusset plates required for structural reasons?