New Delhi: With a length of 12.67km, the Badarpur-Faridabad corridor may not be the longest line in the Delhi Metro network but it will still be unique. Delhi Metro Rail Corporation (DMRC) is using a new technology to build this section. A senior DMRC official said, “We are using U-girders in this corridor. These have been used in the airport line only.” The result: an incredible 1.2km of the viaduct was built in a month, making it one of the fastest corridors being built in Phase III.
Mangu Singh, Managing Director, DMRC, said, “About 65% of the civil work on the Badarpur-Faridabad corridor is already over and 75% of the viaduct has been built.” The fast pace is attributed to the U-girders, which are considerably longer than the usual ones used to build the viaduct or the elevated section of an alignment. So, whereas a normal girder measures only 2.2-2.5m with several spans making one segment, a U-girder span measures 22-27m. “Two pieces of the U-girder make one segment of the viaduct, with each girder being the up and down line. A considerably larger work space is needed to use U-girders, along with extra machinery,” added the official.
For instance, to erect one viaduct segment, four cranes have to launch two sets of the U-girder, which takes 24 hours, the official said. Not surprisingly, the use of U-girders has sped up work on the corridor. Of 12.67km, 5.6km has already been constructed; 1.2km was built in November itself. Officials said the viaduct is expected to be completed by June next year, while work on the station will be completed by November. The various systems—electrical, signalling, tracks and trial runs—should be in place in a few months, added the official. The corridor is scheduled to become operational in March 2015.
DMRC has used I-girders for the turns and crossovers. For instance, the alignment crosses from right to left hand side of the NH-2 near the toll plaza. To cross this, a span length was required that would be able to accommodate a three-lane highway, about 32-33m. Delhi Metro, therefore, designed special piers and pier caps, called extended piers. An elaborate new staging design had to be built to place these piers and pier caps.