The National Highways Authority of India’s (NHAI) objection to the alignment of metro pillars on NH-24 posed a challenge to the Delhi Metro Rail Corporation (DMRC).
Dismantling pillars and building new ones caused a delay of two years -- when there was literally no work on the sections between Mayur Vihar pocket I and IP Extension station and the IP extension- Vinod Nagar depot.
According to the DMRC, dismantling the piers and segments, as well as redesigning new ones, was a major engineering challenge.
“The concrete piers and segments were dismantled in parts using wire saw machines. A wire saw is a powered device that uses a metal wire or cable for cutting. Since the entire work was done along a busy highway, adequate care was taken to ensure that vehicular movement was not hampered,” the spokesperson added.
Two of the three piers erected as per the old plan on either side of NH 24 had to be dismantled while the pier at the median was modified as per the new plan. The entire modification of this stretch, including the demolition of already erected piers and redesigning of the new piers, cost around R 8 crore.
But with technology, the Delhi Metro Rail Corporation (DMRC) has managed to cover the lost time to an extent and hopes that the delay now won’t be more than eight months.
“NH-24 is between Vinod Nagar and Vinod Nagar East stations of the pink line. As per the original plan, piers 114, 115 and 116 passed over NH 24 (near the petrol pumps towards Ghaziabad). While pier 115 was on the median of the highway, piers 114 and 116 were on either side of the NH. All the three piers had been erected. As per the revised plan, both piers 114 and 116 on either side of NH 24 were dismantled. Pier 115 was retained,” said a DMRC spokesperson.
Between the IP Extension and Vinod Nagar metro depots, a portion of the viaduct connects the upcoming metro depot at Vinod Nagar. This is the viaduct through which the trains will hit the main line for operations from the depot.
“As per the original plan, three piers with gaps of 45metres – 60 metres – 45 metres was planned to be constructed to cover the right of way (ROW) of 150 metres. The piers were erected as per the cantilever construction technology. Later, a decision was taken to erect five piers to cover the ROW of 150 metres instead of three and not go for the cantilever technology. By taking this measure, the DMRC will be able to provide a vertical height of 8.5 metres as required by NHAI,” the spokesperson added.