The use of segmental construction in elevated viaduct/bridges was not common in India till DMRC started metro construction in Delhi. The construction of elevated viaducts in city areas if done with conventional cast-in-situ method, will cause great inconvenience as this will need occupation of roads. Further it will take much longer duration to complete the viaduct works. DMRC, therefore, decide to go for segmental construction in big way.
The other advantages of segmental construction are:-
Segmental construction is a cost effective method for a vast range of span lengths and types of structures. Structures with sharp curves and variable super elevation can be put up easily.
Segmental construction allows a reduction…show more content… Besides technical difficulties, the line opening date was scheduled within less than one year.
The Pragati Maidan bridge is an extradosed railway bridge with a main span of 93m. The deck cross-section has a U shape, which allows a great integration of the metro system in the supserstructure. The extradosed cables are wrapped by a concrete beam that allows to regard them as internal prestressing. This beam also enhances the stiffness of the main span.
The construction of the extradosed bridge was a very complicated issue as it had to be constructed over five very busy lines of the Indian Railways. With almost 200 trains, comprising many key trains going towards western and eastern India, passing on the tracks under the new bridge day in and day out, it had to be constructed without any interruption to the train traffic. This is only the second bridge of its kind built over a railway crossing in the earth, the first being in…show more content… Stainless steel car body has been chosen to achieve light weight & less maintenance on account of corrosion. All materials used in the stock are of very high fire rating. Propulsion equipment design has been chosen to achieve high acceleration coupled with highest possible regeneration of energy during braking. Passenger comfort has been kept in focus and the design incorporates two level suspension system with superior bogie design for improved ride quality. State of the art passenger announcement systems and passenger information system coupled with dynamic route map provide requisite information to commuters. High capacity energy efficient on board air conditioners have been provided. Car body construction ensures excellent thermal and acoustic insulation to achieve interior conditions consistent with the requisite international standards. To improve the rail wheel interaction and for mitigation of noise and wheel wear, wheel flange lubricators are used with bogie design suitable for negotiation sharp curves. Braking characteristics are designed for full regenerative braking over almost the complete range of operation and apart from improvement in energy consumption: this would help in reduction in friction braking requirements. DMRC is committed to achieve maximum indigenization and we have achieved notable success and almost 90% of