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Suspension Bridges: Pros and cons along with structural parts details

Articles > Suspension Bridges: Pros and cons along with structural parts details

Introduction to the Suspended Bridges:

Suspended bridges are very common in the era of modern engineering. These bridges are very long, strong, and durable, but still are less dependent on vertical supports of abutments and piers from the downward direction. The bridge span is suspended by two tall towers with the help of metallic ropes, cords, and chains. These bridges look very fragile, but are, indeed very strong and successful in meeting the need for a longer span.

Structural Parts of the Suspended Bridges:

The structural elements of a suspended bridge are categorized into two groups. One is Superstructure and the other is substructure. The upper part of the bridge falls in the category of Superstructure, and composed of beams/girders, deck, two towers, main cable, and the suspension cables, while the substructure is the part of the bridge, which is submerged into the water body. The substructure is composed of abutments/piers and the foundation of abutments.

While defining each part of the bridge, the following lines need consideration.

  1. Two Towers of the Bridges:

The two towers installed at either side of the water body are very tall and strong towers, which hold the whole span of the bridges suspended. These towers are attached to each other at the top with the help of thick and strong cable/rope. The two cables run parallel to each other above all through the bridge span. The towers are the most important element of the bridges which survive the whole load and burden of the bridge as well as the traffic.

  1. Top Cables:

As mentioned in the above lines, two strong cables linking the tops of the poles. These cables escort from the top of one pole and end at the top of the other opposite pole or tower. These cables run parallel all through their way via the bridge span. These cables are very thick and strong. The strength of the cables can be understood, by the load they bear. The whole load of the bridges and the traffic is carried by these two cables.

  1. Suspender Ropes:

The suspension ropes are vertical ropes connecting the top cable with the deck of the bridge. The deck of the bridges is suspended with the top cable by means of the suspension cables.

  1. Deck of the Bridge:

The deck of the bridge, like other bridges, gives way to the traffic. The deck is generally made up of RCC or concrete. The deck is made up of RCC panels placed on the beams or girders.

  1. Beams or Girders:

The girders or the beams of the bridges carry the weight of the deck. The deck panels are placed on the horizontal beams or girders. The beams are made up of RCC, concrete, or truss. The beams of a suspension bridge are not different from the beams of other types of bridges.

  1. Piers:

Piers also known as abutments and pillars, are meant to give vertical support to two opposite ends of the bridge span. The Piers are installed on the submerged concrete foundation. The concrete foundation does not allow the piers to sink in-ground, or underwater crust. The piers and the top towers may be in consolidated form, or in separate form. Whatever the form is, the function still remains the same.

  1. Foundation:

Foundation is the underwater submerged part of the bridges. It has a wider span if compared with that of piers. The wider span of the foundation protects the heavy piers to sink into the ground or the underwater crust. Foundation is made of steel and concrete. The foundation is made with the help of caissons and cofferdams.

Pros and Cons of Suspended Bridges:

These bridges are versatile construction-wise, however, the demerits of the bridge can not be denied. The following are the merits and demerits of the suspension bridges.

Pros of the Bridge:

  1. This type of bridge can span over long distances.
  2. It is inexpensive and economical to build.
  3. Maintenance of the bridge is very easy and low cost.
  4. These types of bridges are aesthetically charming.

Cons of the Bridge:

  1. These bridges are vulnerable to winds and shaky.
  2. It can bear a limited load, because of the lack of direct vertical supports.
  3. It is considered that the suspension bridges are inexpensive, but actually, their construction is not inexpensive as the cost of time consumed during its construction makes it costly.
  4. It can not be stiff to support rail traffic. It used to be very flexible in order to avoid damage caused by winds.


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