By ashleykaren
Larsen & Toubro has broken through on the Mumbai-Ahmedabad High-Speed Rail corridor project’s first mountain tunnel.
The NATM-constructed tunnel close to the village of Zaroli in Gujarat is 350m long, has a height of 10.25m, and a 12.6m diameter. It is a single tube horseshoe shape, was excavated in 10 months, and will house two tracks. Also, it is the first of seven mountain tunnels to be constructed by NATM on the path.
Tunnel construction comprised marking drill holes on the tunnel face, drilling holes, charging explosives, controlled blasting, muck removal, and installation of primary support containing steel ribs, lattice girder, shotcrete, and rock bolts.
The 508km Mumbai-Ahmedabad High-Speed Rail project, known as the MAHSR Bullet Train project also, will link Mumbai with Ahmedabad in Gujarat.
It incorporates 465km of viaducts, 12 stations, three rolling stock depots, 28 steel bridges (containing a 2km bridge over the Vaitarna river), and nine tunnels, such as India’s first undersea tunnel. The 7km subsea section is part of a 21km tunnel between Bandra-Kurla Complex and Shilphata in the Maharashtra state.
NHSRCL (the National High-Speed Rail Corporation) has granted several packages to Larsen & Toubro, comprising the C-3 package, which contains a 135km alignment from Shilphata to Zaroli village, including 124km of viaducts and bridges, six mountain tunnels, 36 crossings (encompassing 12 steel bridges), and three elevated stations, the civil and building works packages C-4 (237km); C-5 (8.2km); and C-6 (87.5km); and the ballastless trackworks package T-3.
