The Delhi Metro Rail Corporation (DMRC) on Monday achieved a significant construction milestone in Phase 4 with the completion of an underground tunnel between Chhatarpur Mandir and IGNOU Station on the Tughlakabad-Aerocity corridor.
The breakthrough of the Tunnel Boring Machine (TBM) at the IGNOU Station site took place in the presence of Anand Mohan Bajaj, Deputy Comptroller and Auditor General, Commercial; Pramod Kumar, Additional Deputy Comptroller and Auditor General; Vikas Kumar, MD, DMRC and other senior officials.
“A TBM broke through this morning at IGNOU Station after boring an 1,475 metre-long tunnel. This tunnel breakthrough was achieved using a mammoth 97-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,” said Anuj Dayal, Principal Executive Director, Corporate Communications, DMRC.
He said the breakthrough on the other parallel tunnel is planned to be achieved in the month of March 25.
The official informed that this new tunnel has been constructed at an average depth of approximately 26 metre making it one of Delhi Metro’s deepest tunnels. The tunnel on the Magenta Line at Hauz Khas has been built at a depth of about 30 metres. About 1,048 rings have been installed in the tunnel, with an inner diameter of 5.8 metre.
Dayal said the tunnelling drive for this tunnel started on December 4, 2023 and challenges of steep gradient along with varied geology comprising mica and hard rock were encountered due to which the screw auger got damaged and was replaced during the drive.
Informing that all necessary safety precautions were taken during the construction of the tunnel below the existing viaduct and built-up structures, he said 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 km of underground lines are being constructed. The Aerocity-Tughlakabad corridor has underground sections totalling 19.343 km.