The Delhi Metro Rail Corporation (DMRC) today achieved a significant construction milestone with the completion of the underground tunnel between Maa Anandmayee Marg and Tughlakabad Railway colony station on the Tughlakabad-Aerocity corridor of Phase-IV which is also known as Golden Line.
The breakthrough of the Tunnel Boring Machine (TBM) at the Tughlakabad Railway colony station site of the Delhi Metro took place in the presence of Dr. Pankaj Kumar Singh, Hon’ble Minister for Health & Family Welfare, Transport, Information Technology, Govt. of NCT of Delhi , Dr. Vikas Kumar, Managing Director/DMRC and other senior officials.
A TBM broke through this morning at Tughlakabad Railway colony Station after boring a 0.792-kilometre -long tunnel. This tunnel breakthrough was achieved using a mammoth 96-metre-long TBM. Two parallel circular tunnels for up and down movement are being constructed on this stretch as part of the Aerocity–Tughlakabad corridor. The breakthrough on the other parallel tunnel is expected to be achieved in July 2025.
This new tunnel has been constructed at an average depth of approximately 18 meters. About 566 rings have been installed in the tunnel, with an inner diameter of 5.8 meters. The tunnel has been built using the proven technology of EPBM (Earth Pressure Balancing Method) with a concrete lining made of precast tunnel rings. These tunnel rings were cast at a fully mechanized casting yard set up at Mundka. The concrete segments were cured with a steam curing system to achieve early strength.
All necessary safety precautions were taken during the construction of the tunnel below the existing built-up structures. Ground movements were monitored with highly sensitive instruments fixed on nearby structures, ensuring that there was no settlement anywhere.
As part of the Phase 4 work approved so far, 40.109 kilometres of underground lines are being constructed. The Aerocity-Tughlakabad corridor has underground sections totaling 19.343 kilometres.
A TBM is a machine used to excavate tunnels with a circular cross-section through various soil and rock strata. They can be designed to bore through anything from hard rock to sand. TBMs have revolutionized tunneling work worldwide, enabling tunnels to be bored without disturbing buildings and other surface structures.
TBMs are particularly useful for underground tunneling work in congested urban areas. DMRC has been using TBMs for its tunneling work since Phase 1. In Phase 3, when approximately 50 kilometres of underground sections were built, about 30 TBMs were deployed in the national capital.
