PRESTRESSED AND SUSPENDED BRIDGES

I support this view but differ that PSC can only be on simple supported spans & length is up to 30M. In fact in 1999 I have constructed 90 M long continuous box girder of 30m span. I ahve also executed 50 M long I-girder simply supported. At present I am executing 45M long simple supported PSC box girder. In fact span any span can be prestressed. Similarly suspended bridges also very popular for pedestrail bridges very common in hilly areas. Its span can also be small. However suspension bridges & PSC bridges have no comparision at all becuase both are different technically & conceptually.

I agree with Mr Ghosh. Suspension bridges are now need of the hour. The difference between techniques adopted in suspension bridge and prestressed bridge is not the question as the suspension bridges can also have prestrssed element. It is the abscence of supporting intermediate pillars (which transfer the load of deck to ground) in suspension bridge which makes it cost effective for longer spans. Hence when we go in for bridges over wider rivers or other locations having significant coverage area, we must adopt suspension bridges only

I agree that presteresssed bridge design offer the most moder solutions to constructability. However in the current debate is over the suspended bridge designs would effectively overcome them over the economic vaibility.They require expertise in construction, design , Logistics . So on the decision of adopting their design at the first instance the study over the suspeended brige option becomes mandatory.

While the most interchanges in dubai and world over constructed recently has opted for the suspended system due to easy and fast constuctability as compared to dubai metro elevated rail system which opted on prestessed system design.

Moreover now the recent fusion of cable stayed suspension bridges and prestessed bridges has provided the most viable option as in Bandra Worli sea link option.

In india the thing we go for prestressed bridges is that we are not ready to try new things and also the thing is that there is no sufficient expertise available to construct these types of bridges.If you see all the countries they have every bridges uniquely,but in india it is the same T-beam bridge everywhere exception is the new bombay bridge.but may b it is costlier but i am not sure.