Breakthrough at Vasant Kunj station marks milestone in Phase 4 tunnelling

In a significant development for Delhi Metro’s Phase 4 expansion, the Delhi Metro Rail Corporation (DMRC) on Wednesday announced the successful completion of a 1.55-km underground tunnel between Kishangarh and Vasant Kunj stations on the Golden Line (Aerocity-Tughlakabad corridor). A tunnel boring machine (TBM) achieved the breakthrough at Vasant Kunj station, marking a major construction milestone on the route.

The newly completed tunnel, constructed at an average depth of 22.86 m, is part of a twin-tunnel system designed for up-and-down metro movement.

The breakthrough of the parallel tunnel on the same stretch was earlier achieved on March 6.

Built using the earth pressure balancing method (EPBM), the tunnel includes 1,105 precast concrete rings with an internal diameter of 5.8 m.

The segments for these rings were manufactured at a dedicated, fully mechanised casting yard in Mundka using steam curing to ensure early strength and durability.

DMRC officials said all safety measures were strictly followed during the tunnelling, with real-time monitoring of ground movement through sensitive instruments installed on nearby structures.

“There was no settlement or structural disturbance reported during the operation,” the corporation said.

The Aerocity-Tughlakabad corridor, which includes 19.343 km underground sections, is part of the broader Phase 4 project, which involves 40.109 km underground track.

The use of TBMs has been central to DMRC’s expansion in the Capital, especially in dense urban zones where minimal surface disruption is crucial.