New Delhi, India (Metro Rail Today): The National High Speed Rail Corporation (NHSRCL) opened the technical bids for the contract package MAHSR-C2 today in New Delhi. The bids were invited for the tunneling works for a 21 km (approx.) long tunnel including a 7 km undersea tunnel using Tunnel Boring Machine (TBM) and New Austrian Tunneling Method (NATM) for Mumbai-Ahmedabad High Speed Rail corridor.
As per the information shared by NHSRCL, two construction firms namely Larsen & toubro Ltd (L&T) and Afcons Infrastructure Ltd have submitted their bids for construction of 20.377 km undersea tunnel for Mumbai-Ahmedabad High Speed Rail Corridor.
The scope of work includes the design & construction of Tunnelling Works including Testing and Commissioning for Double Line High-Speed Railway using Tunnel Boring Machine (TBM) and New Austrian Tunnelling Method (NATM) between Mumbai Underground Station at Bandra-Kurla Complex (MAHSR Km. 0.773) and Shilphata (MAHSR Km. 21.150) in the State of Maharashtra for the Project for Construction of Mumbai-Ahmedabad High Speed Rail Corridor.
The tunnel will be between the underground station at Bandra-Kurla Complex and Shilphata in the State of Maharashtra.
The 7 km (approx.) undersea tunnel at Thane Creek (Intertidal Zone) will be the First undersea tunnel to come up in the country.
The tunnel will be a single tube tunnel to accommodate twin tracks for both up and down tracks. 39 equipment rooms at 37 locations will also be constructed in adjoining tunnel locations as part of the package.
To construct this tunnel, TBMs with a cutter head of 13.1 Meter diameter will be used. Usually, 5-6 Meter Diameter cutter heads are used for urban tunnels used in MRTS – Metro system.
Three Tunnel Boring Machines will be used to make about 16 km of the tunnel portion and the remaining 5 km will be through the New Austrian Tunnelling Method (NATM).
This tunnel will be about 25 to 65 Meters deep from the ground level and the deepest construction point will be 114m below the Parsik hill near Shilphata.
Three shafts at BKC (under package C1), Vikhroli, and Sawli at approximate depths of 36, 56 and 39 Meter depths respectively will facilitate the construction. The inclined Shaft of 42 meters at Ghansoli and the Tunnel portal at Shilphata will facilitate the construction of approx. 5 km of the tunnel through the NATM tunnelling method.
The 508 km Mumbai Ahmedabad High Speed Rail Corridor will connect Ahmedabad to Mumbai with 12 stations.