The Delhi Metro Rail Corporation (DMRC) is undertaking the development of over 40 kilometers of underground corridors as part of its Phase 4 expansion, which is a significant portion of the overall 86 kilometers of new lines being laid across five corridors. This underground expansion represents approximately 50% of the total lines being developed in Phase 4, and it includes the construction of 27 underground stations.
DMRC has already completed a small underground section of about 2 kilometers from Janakpuri West to Krishna Park as part of the Magenta Line extension. The new underground sections will be developed using cutting-edge technologies and will pass through challenging areas such as crowded residential and commercial zones in Sadar Bazar, Nabi Karim, Mehrauli Badarpur Road, and Ajmal Khan Park. To manage the complex tunneling work, DMRC uses Tunnel Boring Machines (TBMs), which are capable of cutting through various soil and rock types, making them ideal for congested urban areas. TBMs have been in use since Phase 1, and in Phase 3, 30 TBMs were deployed for around 50 kilometers of underground sections. A portion of the Aerocity-Tughlakabad corridor will also use the New Austrian Tunneling Method (NATM), which has been previously used successfully by DMRC in earlier phases.
The underground sections in Phase 4 include:
- Aerocity-Tughlakabad: Approximately 19 kilometers.
- Janakpuri West-RK Ashram Marg: About 9 kilometers.
- Inderlok-Indraprastha: Over 11 kilometers.
- Majlis Park-Maujpur and Lajpat Nagar-Saket G Block: These sections will not have underground stations.
DMRC is ensuring that the construction is closely monitored to safeguard the condition of the buildings above ground, employing necessary instrumentation for real-time monitoring of the affected areas.
