Comparison Between Two Beam Bridges

Figure 1 shows a two-lane road beam bridge.

Beam bridge 1.
Beam bridge over a river.

The beams are made of prestressed concrete; the span s ≅ 20 m, the height h ≅ 0.7 m, and the width (per beam) ≅ 1 m. The beams are placed side-by-side and supported by two column bents. Figure 2 shows a single-lane road beam bridge with steel trusses.

Beam bridge 2.
Beam bridge with trusses over a river.

The beam type and geometry are equal to beam bridge 1, and the support consists of wall piers. Figure 3 shows a bridge entrance.

Bridge entrance.
Entrance of a beam bridge with trusses.

The truss is connected to the walkways; the height h1 ≅ 3 m, and the members are made of built-up sections. Figure 4 shows a connection between two members and the walkway.

Truss to walkway connection.
Connection between truss and walkway.

The connection consists of a base plate and six anchor bolts. Figure 5 shows a schematic three-dimensional view of a span of beam bridges 1 and 2.

Beam bridges 1 and 2.
Three-dimensional drawing of a span of two beam bridges.
  • What is the purpose of the truss?