The Delhi Metro Rail Corporation (DMRC) has achieved a major construction milestone in Phase 4 with the completion of the underground tunnel between Chhatarpur and Chhatarpur Mandir Station on the Tughlakabad-Aerocity corridor.
An EPBM broke at Chhatarpur Mandir Station after boring an 860m long tunnel. This tunnel breakthrough was achieved using a mammoth 97m long EPBM. Two parallel tunnels have been constructed for this stretch as part of the Aerocity–Tughlakabad corridor. The breakthrough on the other twin tunnel was achieved on 21stAugust 2024.
This new tunnel has been constructed at an average depth of approximately 12m, with some 613 rings installed creating an inner diameter of 5.8m. The concrete lining is made of precast tunnel rings, all 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.
The tunnelling work involved numerous challenges, such as shifting a 66KV electrical HT line. The TBM also had to pass below the existing Yellow Line viaduct without disrupting Metro train operations on the Yellow Line.
All necessary safety precautions were taken during the construction of the tunnel below the existing viaduct and built-up structures. Ground movements were monitored with highly sensitive instruments fixed on nearby structures, ensuring that there was no settlement.
As part of the Phase 4 work approved to date, 40.109km of underground line is being constructed. The Aerocity-Tughlakabad corridor has underground sections totalling 19.34km.
Comments: