New Delhi: The Delhi Metro Rail Corporation (DMRC) has successfully completed a highly challenging underground tunnel for the Magenta Line Phase-IV extension, passing directly beneath the operational Red Line at Pulbangash without affecting train operations. This achievement underscores DMRC’s advanced engineering capabilities and its commitment to safe and efficient urban infrastructure development in densely populated areas.
Engineering Feat Below Operational Metro Line
The tunnel, situated between Pulbangash and Sadar Bazar, had to be constructed below a viaduct that carries lakhs of passengers daily and rests on sensitive open foundations. To ensure complete structural safety, DMRC employed Tube-a-Manchette (TAM) grouting, drilling 180 boreholes and injecting high-strength cement grout to stabilise the soil before excavation.
This method strengthened the ground and minimized the risk of settlement, allowing tunnelling to proceed safely beneath an active metro corridor.
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Advanced Monitoring Ensures Safety
Throughout the tunnelling operation, DMRC deployed an extensive network of real-time monitoring instruments, including:
- Surface settlement markers
- Inclinometers
- Pier tilt meters
- Load cells
- Automatic Total Station
Engineers monitored data round the clock, ensuring that all readings remained within safe limits. This continuous monitoring enabled the tunnel construction to progress smoothly without compromising the safety of passengers or the structural integrity of the Red Line viaduct.
Next Steps and Phase-IV Expansion
With the down-line tunnel completed, work on the up-line section is now underway. The project forms part of Delhi Metro’s Phase-IV expansion, aimed at enhancing connectivity on the Magenta Line and supporting the city’s growing transportation needs.
The successful completion of this tunnel without a single day of service disruption highlights DMRC’s ability to execute complex urban infrastructure projects with precision, technological innovation, and adherence to stringent safety standards.
About DMRC
The Delhi Metro Rail Corporation (DMRC) is a leading public sector enterprise responsible for the development, operation, and maintenance of metro rail systems in Delhi and other cities. Known for its engineering excellence, timely project delivery, and focus on safety, DMRC continues to play a pivotal role in strengthening India’s urban transportation infrastructure while setting benchmarks in public sector urban mobility projects.
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