General Information

Figure 1 shows a pedestrian suspension bridge.

Pedestrian suspension bridge.
Pedestrian suspension bridge in a park
Type Three-span suspension bridge
Main span ≅ 40 m
Deck width ≅ 1.5 m
Deck width to main span ratio ≅ 1:27
Pylon Reinforced concrete (H-shaped)
Girder Steel truss

Truss Girder

Figure 2 shows a schematic partial three-dimensional view of a truss girder sector.

Truss girder.
Three dimensional drawing of a truss girder

The truss girder consists of upper and bottom chords, diagonals, horizontal ties, and cross-braces (red marked); verticals are therefore not applied. The diagonals of side 1 are inclined in the opposite direction to the diagonals of side 2, and the cross-braces are alternately inclined in the opposite direction. Figure 3 shows a side view of a truss girder sector.

Truss girder.
 Truss girder of a pedestrian suspension bridge

The truss girder carries also two pipes.

  • What are some possible reasons for using the above shown truss girder type?
  • Main Cables to Pylon Connection Position

    Figure 4 shows a pylon viewed from the front.

    Pedestrian suspension bridge tower

    Enlarged view 1 is shown in figure 5.

    Enlarged view 1.
    Top end region of a pedestrian suspension bridge pylon

    The red arrows represent the vertical component forces of the main cables, which are acting on the horizontal braces.

  • How does the main cables to pylon connection position affect the pylon structural efficiency?
  • Entrance Elements

    Figure 6 shows the bridge entrance on shore 1.

    Bridge entrance.
    Entrance elements of a pedestrian suspension bridge

    Entrance element A is shown in figure 7.

    Entrance element A.
    Enlarged view of an entrance element of a pedestrian suspension bridge

    An entrance element consists of a reinforced concrete column and a steel structure, which is connected to the reinforced concrete column by a base plate and anchor bolts. The main cable passes through the steel structure via a hole.

  • Does the bridge have a structural safety or serviceability problem without the entrance elements?
  • Hanger Cables to Main Cables Connection

    Figure 8 shows a hanger cable to main cable connection.

    Hanger cable to main cable connection.
    Connection between hanger cable and main cable of a pedestrian suspension bridge

    The hanger cable passes over the main cable, and the U-bolt clamp passes over the hanger cable.

  • What are the main problems?