General Information

Figure 1 shows a pedestrian suspension bridge.

Suspension bridge.
Single-span suspension over a river
Type Single-span suspension bridge
Main span ≅ 80 m
Deck width ≅ 1.5 m
Deck width to main span ratio ≅ 1:53
Pylon Reinforced concrete
Girder Steel transverse beam

Anchorage

Figure 2 shows an anchorage.

Main cable anchorage.
Main cable anchorage of a single-span suspension bridge

The main cables are connected to the front region of the anchor block, and the short cables are connected to the mid-region of the anchor block. The main and the short cables are of the same type and size and are connected as shown in figure 3.

Main cable to short cable connection.
Cable-to-cable connection of a single-span suspension bridge

The two cables are overlapped and fixed with U-bolt clamps. Figure 4 shows a schematic lateral view of an anchorage.

Lateral view.
Anchorage of a single-span suspension bridge

The short cables are sagging.

  • Do the short cables transfer load from the main cables to the anchor block?
  • Bottom Cables

    Figure 5 shows the main span.

    Suspension bridge with bottom cables.
    Suspension bridge with two bottom cables

    There are two bottom cables; they run over the girders and are anchored to the pylons. Figure 6 shows a bottom cable.

    Bottom cable.
    Connection between bottom cable and girder of a suspension bridge

    The bottom cable passes through the holes of the eye bolts used for the hanger-to-girder connection. The pylon anchorage is shown in figure 7.

    Pylon anchorage.
    Bottom cable anchorage at the pylon

    The bottom cable is vertically and horizontally deviated at the first girder and connected to horizontal rebars of the pylon's bottom cross beam. The bottom cable termination consists of a cable thimble and U-bolt clamps.

  • Does the bridge have a structural safety or serviceability problem without the bottom cables?