Mumbai-Ahmedabad bullet train: The breakthrough in the first mountain tunnel in the Mumbai-Ahmedabad high speed rail corridor, popularly called the bullet train, was achieved on Thursday in Valsad in Gujarat, the National High Speed Rail Corporation Limited (NHSRCL) said,
The tunnel, which is located some 1 kilometre away from Zaroli village in Umbergaon taluka in Valsad in the neighbouring state, was completed in 10 months using the New Austrian Tunnelling Method (NATM), the NHSRCL release said.
“The comprises a tunnel, a tunnel portal, and other connecting structures like a tunnel entrance hood. The 350-metre long tunnel has a diameter of 12.6 metres and a height of 10.25 metres. The single tube horseshoe-shaped tunnel will have two high-speed train tracks passing through it,” it said.
As per the shareholding pattern, the government of India will pay Rs 10,000 crore to the NHSRCL, while the two states involved, Gujarat and Maharashtra, are to pay Rs 5,000 crore each.
The rest comprises a loan from Japan.
The tunnel is being constructed by New Austrian Tunnelling Method (NATM) which includes the following procedure:
Marking of drill holes on the tunnel face
Drilling of holes
Charging of explosives
Removal of muck (blasted rock pieces)
Installation of primary support which includes steel ribs, lattice girder, shotcrete, rock bolts based on the type of rocks as assessed by geologist after each blast
Salient features of the mountain tunnel:
Total Tunnel Length: 350 m
Diameter of Tunnel: 12.6 m
Height of Tunnel: 10.25 m
Tunnel Shape: Single tube horse-shoe shaped
Number of tracks: 2 Tracks