The Delhi Metro Rail Corporation (DMRC) and contactor HCC have achieved a major construction milestone on Phase 4 of the Delhi Metro with the completion of tunnelling work between Krishna Park Extension and Keshopur on the Janakpuri West – RK Ashram Marg corridor. Employing a 6.52m diameter Terratec EPBM, the team broke through on the DC-06 contract package at Krishna Park Extension after boring the 1.4km long, 5.8m i.d. tunnel.
Twin parallel tunnels have now been constructed on this stretch, which is part of a 2.2km long underground section from Janakpuri West to Keshopur. The work on the parallel tunnel on this section was completed in December last year.
This new tunnel stretch is a continuation of the earlier Magenta line tunnel that was constructed for the presently operational ‘Botanical Garden – Janakpuri West corridor’. The tunnel has been constructed approximately at a depth of 14 to 16m. About 2,000 rings have been installed in the tunnel. The alignment of the tunnel runs along the Outer ring road and below multi-storied built-up structures. The geology is composed of silty sand, fine sand & sandy silt and clayey silt with the segment lining comprising RC segments with an outer diameter of 6,350mm, inner diameter of 5,800mm and width of 1,400mm.
The completion of this stretch is a significant achievement for DMRC since this work faced repeated constraints due to the Covid – 19 pandemic. The workforce was retained – following all the guidelines – and the work schedule planned accordingly.
70% of the project work completed to date is expected to be handed over to DMRC by Dec-2023, with the entire Janakpuri West – RK Ashram Marg corridor being ready by September, 2025.