India’s Bullet Train project achieved another milestone on Thursday with the breakthrough of a mountain tunnel. This is the first mountain tunnel for the Mumbai-Ahmedabad High Speed Rail (MAHSR) corridor project. The entire corridor will have seven mountain tunnels.
Location and Completion of Mountain Tunnel:-
The National High Speed Rail Corporation Limited (NHSRCL) has completed the mountain tunnel in a short span of 10 months. It is located at around 1 km away from Zaroli Village of Umbergaon Taluka in Valsad district of Gujarat. The tunnel structure comprises tunnel, tunnel portal and other connecting structures like tunnel entrance hood.
How was the NHSRCL’s first mountain tunnel constructed?
The NHSRCL is constructing the tunnel using the New Austrian Tunnelling Method (NATM). This includes following procedure:-
- Marking of drill holes on the tunnel face
- Drilling of holes
- Charging of explosives
- Controlled Blasting
- 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
Features of Bullet Train Project’s first mountain tunnel:-
- The total length of the tunnel is 350 metre.
- The diameter of the tunnel is 12.6 metre.
- The height of the tunnel is 10.25 metre.
- The tunnel is Single tube horse-shoe shaped.
- A total of 2 tracks will be laid.
Setting up of new Track Slab Manufacturing Facility
Last week, the NHSRCL opened a new Track Slab Manufacturing Facility (TSMF) at Gujarat’s Anand, for the production of Track Slabs required for the construction of ballast less track works for the MAHSR project. It will produce around 60 slabs per day.