This type of bridges are constructed by suspending the deck slab using suspension cables. The roadway is hanged using steel cables which are connected to two towers and secured by anchors on both ends of the bridge.
In addition to the deck slab, the truss system is also featured with truss system just beneath the deck which helps to stiffen and to keeps the deck in precise position to reduce the tendency of the roadway to sway.
When the load is applied to the suspension bridge, the deck slab possess compression and then travels up the ropes, cables or chains to transfer the compression to the towers. The towers then dissipate the compression directly into the earth by anchors.
The supporting cables which run parallel to the bridge possess tension forces, and these are connected to anchorages. Bridge anchorages are massive concrete blocks which serve in dissipating the tension force to the ground
Bridge anchorages are essentially solid rock or massive concrete blocks in which the bridge is grounded. Tensional force passes to the anchorages and into the ground. The span length of Suspension bridge is in between 150m-2000m
Advantages of Suspension bridge:
- Strong and lightweight.
- These type of bridges provide long span which helps in crossing the river.
Disadvantages of Suspension bridge:
- Expensive to build.
- Prone to sway and ripple with the wind, so this type of bridges are not suitable for railways.