The Delhi Metro achieved the fourth and final tunnel breakthrough at Janpath metro station at 5-38 p.m. on Monday after completing a 1,492-metre-long tunnelling on the Down Line from Mandi House to Janpath. The internal diameter of the tunnels is 5.8 metres.

The maximum depth of the tunnel is 24 metres below the earth’s surface and the excavated earth was deposited at Mukundpur Depot. An ‘Earth Pressure Balancing Type’ TBM was used to concrete the tunnel. Some of the most advanced instruments were used for ground and structure monitoring.

The tunnel passes beneath important buildings such as the American Center, Nepal Embassy, Fulbright House, Antriksh Bhawan, Scindia House, Janpath Market and Jeevan Prakash Building.

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