The Delhi Metro Rail Corporation (DMRC) has reached a significant milestone in Phase 4 construction by completing its longest underground tunnel on the Tughlakabad-Aerocity corridor (Golden Line). A Tunnel Boring Machine (TBM) achieved a breakthrough at Maa Anandmayee Marg, marking a major engineering achievement in the ongoing expansion of Delhi Metro’s network.
Breakthrough Details:
- Milestone Achieved: The breakthrough was accomplished at Maa Anandmayee Marg Station.
- Tunnel Length: A 2.65-kilometre-long underground tunnel was completed.
- TBM Used: The 105-metre-long Tunnel Boring Machine (TBM) ‘AMRIT’ was deployed for the task.
- Depth: The tunnel was constructed at an average depth of 16 meters.
- Rings Installed: 1,894 precast concrete rings, each with an inner diameter of 5.8 meters, were used for the tunnel lining.
Technical Challenges and Solutions:
- Navigating Hard Rock Strata: The tunneling work involved excavation through challenging geological conditions, including hard rock.
- Sewer Line Relocation: Critical sewer lines were relocated to enable the tunnel construction.
- Advanced Technology: The Earth Pressure Balancing Method (EPBM) with precast concrete rings ensured stability and precision.
- Safety Measures: Ground movements were continuously monitored using sensitive instruments to prevent settlement or structural damage.
Phase 4 Overview:
- Underground Construction: Phase 4 includes a total of 40.109 kilometres of underground corridors, with 19.343 kilometres on the Aerocity-Tughlakabad corridor.
- Civil Contractor: The tunneling work was executed by M/s Afcons.
- Upcoming Milestone: The second parallel tunnel is expected to achieve a breakthrough in January 2025.
TBM Technology at DMRC:
- Efficiency: TBMs are capable of boring through various soil and rock strata with minimal disruption to surface structures.
- History with DMRC: Since Phase 1, DMRC has utilized TBMs extensively, deploying around 30 machines during Phase 3 alone for approximately 50 kilometres of underground sections.
- Urban Application: TBMs are especially effective for tunneling in congested urban areas, allowing safe and precise construction beneath built-up environments.
Conclusion:
This breakthrough signifies another remarkable step forward for DMRC as it continues to expand Delhi’s metro network using advanced engineering and construction techniques. The achievement underscores DMRC’s commitment to sustainable and efficient urban transport infrastructure, setting a benchmark for future metro projects in India.
Source: DMRC – Press Release | Images Credit: DMRC
