General Information

Figure 1 shows a pedestrian truss bridge.

Pedestrian truss bridge.
Steel truss bridge over a highway
Main span ≅ 35 m
Type Through truss bridge
Truss material Steel
Truss height ≅ 2.5 m
Deck width ≅ 2 m

Built-Up Section

Figure 2 shows a side view of a truss sector.

Truss.
Steel truss of a pedestrian overpass

The upper and bottom chords consist of built-up sections; the diagonals, of square hollow profiles. An upper chord viewed from the front and the side are shown in figures 3 and 4, respectively.

Upper chord (front view).
Front view of a steel composite profile

The built-up section consists of two side-by-side placed H-profiles, an upper plate, and a bottom plate. Upper-and bottom plates are connected to the H-profiles by welding.

Upper chord (side view).
Side view of a steel composite profile
  • What are some possible reasons for using the above shown built-up section instead of a square hollow profile?
  • Bridge Drainage

    Figure 5 shows a main span sector.

    Main span.
    Bridge entrance region

    Drainage pipes 1 and 2 are embedded in the abutment cap and abutment. Figure 6 shows the abutment cap, while figure 7 shows the bottom region of the abutment.

    Abutment cap.
    Drainage pipes embedded in the abutment cap
    Abutment (bottom region).
    Drainage pipes outlet in the abutment bottom region

    The thickness of the abutment t ≅ 50 cm, and the diameter of a drainage pipe ≅ 10 cm; the outlets are toward the street side.

  • Do the drainage pipes affect the structural behavior of the abutment cap and abutment?
    What are some possible reasons for embedding the drainage pipes in the abutment cap and abutment?