Larsen & Toubro (L&T) has completed the breakthrough of Mountain Tunnel-07 (MT-07) under the Mumbai-Ahmedabad High Speed Rail (MAHSR) C-3 package, marking its third tunnel breakthrough in the past five months. Situated in the Sahyadri hills near Ambesari village in Maharashtra’s Dahanu Taluka, the 417-metre tunnel was excavated over 516 days using the New Austrian Tunnelling Method (NATM) with 117 controlled blasts.
Built to carry both up and down tracks, the 12.6-metre-wide tunnel was constructed amid complex geological conditions with continuous monitoring and support measures such as shotcrete, rock bolts and lattice girders. Safety was further enhanced through advanced instruments including seismographs, 3D targets and Surface Settlement Points.
The 135.45-km C-3 section of the Mumbai-Ahmedabad bullet train project stretches from Shilphata in Thane to Zaroli near the Maharashtra-Gujarat border. The package comprises stations at Thane, Virar and Boisar, nearly 124 km of viaducts, seven mountain tunnels covering 6 km, 2.3 km of steel bridges and 5 km of special earth structures. The latest breakthrough represents another key step in the progress of India’s first high-speed rail corridor.
