The National High-Speed Rail Corporation Limited (NHSRCL) on Friday said Afcons Infrastructure Limited has won the bid between two technically qualified financial bids to construct a 21-km tunnel, including 7 km under sea, as part of the Mumbai-Ahmedabad line. Bid a low amount. Bullet Train Project.
The NHRSCL said it had received bids from Afcons Infrastructure Ltd and Larsen & Toubro Ltd for construction of the tunnel, which will stretch from the proposed underground station at Mumbai’s Bandra Kurla Complex to Shilphata in neighboring Thane district.
New Austrian tunneling method being used
“The tunnel will be a single-tube twin-track tunnel with a diameter of 13.1 metres. Out of 20.37 km, 15.42 km will be tunneled with three TBMs (Tunnel Boring Machines) and the remaining 4.96 km will be built using the New Austrian Tunneling Method ( NATM) The depth of the tunnel will be in the range of 25 m to 65 m.
“The tunnel will cross Thane Creek and the survey work below the creek was done using underwater static refraction technique.
An NHSRCL spokesperson said, the deepest construction point will be 114 meters below Parsik hill near Shilphata.
The spokesperson said that TBMS with 13.1 meter diameter cutter head would be used, which would be much larger than the 5-6 meter diameter cutter head used for metro rail systems etc.
Total cost around Rs 1 lakh crore. The high speed corridor between Mumbai and Ahmedabad is being built at a cost of Rs 1.08 lakh crore.
While the major part of the cost is covered by a loan from Japan, the rest will be contributed by the central government and the governments of Maharashtra and Gujarat.
(with PTI inputs)