Question

What is the significance of the simply supported beam bridge and what is the implication simply supported beam is applied on the bridge?

Answer 1

Significance of simply supported beam bridge:

It is simple structure where bridge span is supported by an abutment or pier at each end of the bridge. Usually there are no transfer of moments. So this structure type is called simply supported bridge.

Main advantages of simply supported beam is , when supporting pier or abutment sinks, there will be no consequence to the spanning beams. But if it happens in continuous beam, extra additional moments are come in to picture.

Another advantage of simply supported beam is, due to temperature variations in the nature, there is a contraction or expansion. These effects are minimum or negligible in this beam. As far cost is concerned , simply supported beam bridge are better and durability is also high.

Implications :

If the bridge spans are simply supported, differential settlements will not cause any additional moments in the structure. Hence structure will be safe. Whereas if the structure consists of more continuous beam spans, there is high chances of differential settlement and which inturn causes failure of super structure.

Some problems with simply supported beam bridge are , it consists of many joints in the deck. Sometimes we experience unpleasant drive due to small movement in the bridge. Although it hives flexibility to the structure. There will no small discomfort.

But even small settlements can be corrected by jacking up the deck and even if we consider construction part, it requires less materials and it is easy to execute the plan.