DMRC today achieved the fourth & final tunnel breakthrough of Delhi Metro’s Phase - III project at Janpath Metro station in the presence of Mr. Mangu Singh, Managing Director, DMRC & other Directors.
The breakthrough was achieved at 5:38 PM by completing 1492 meters long tunneling on the Down line of the Mandi House– Janpath stretch.
This maximum depth of the tunnel is 24 meters below the earth’s surface. It passes beneath a lot of important buildings of Central Delhi like the American Centre, Nepal Embassy, Fulbright House, Antriksh Bhawan, Scindia House, Electrical Sub Station, Janpath Market and Jeevan Prakash Building.
The excavated earth was deposited at Mukundpur Depot. Earth Pressure Balancing Type TBM was used to concrete the tunnel. The TBM cutter head rotated at the rate of 1 to 2.3 RPM.
The internal diameter of the tunnel is 5.8 mts. The casting of the segments was done at the Mundka Casting Yard.
The TBM used to make the tunnel is from Herrenknecht.
The instruments used for ground and structure monitoring were: MPBS, Stand Pipe Piezometer, Vibrating Wire, Piezometer, Crack Meter, Tilt Plate, Soil/Pavement Point, Building Settlement Point and Bireflect Target.
M/s Pratibha CRFG JV is the contractor for the tunneling work of the stretch from Central Secretariat to Mandi House. The stations at Janpath and Mandi House are also being constructed by the same contractor using Cut & Cover technique.
