Maharashtra: Construction of India's First 21 Km Undersea Bullet Train Tunnel Advances To Connect Mumbai's BKC With Shilphata

The tunnel will connect the underground station at the Bandra-Kurla Complex (BKC) in Mumbai to Shilphata.

According to officials from the National High Speed Rail Corporation, tunneling works are progressing rapidly. Of the total length, 16 km is being excavated using Tunnel Boring Machines (TBMs), while the remaining 5 km utilizes the New Austrian Tunneling Method (NATM).

About The Key Developments

Key developments include the completion of 100% secant piling at both Shaft-1, located at BKC, and Shaft-2 in Vikhroli, with Shaft-1 reaching a depth of 36 meters and Shaft-2 at 56 meters, where approximately 92% of excavation is complete. Additionally, excavation for Shaft-3 at Sawli, near Ghansoli, has concluded, setting the stage for the first TBM to be lowered by the end of the year.

"At the Shilphata portal, construction work has also made significant strides, with 200 meters of excavation completed. This area marks the NATM end of the tunnel. An Additional Driven Intermediate Tunnel (ADIT), measuring 394 meters, has been completed in just six months, enabling two additional NATM excavation fronts, which have contributed over 700 meters of tunneling" said an official.

What Features Does The Additional Driven Intermediate Tunnel Have?

The ADIT features internal dimensions of 11 meters by 6.4 meters and will facilitate direct vehicular access to the main tunnel during both construction and operational phases. It is also designed for emergency evacuations.

"To ensure safety and structural integrity, various geotechnical instruments, including inclinometers, vibration monitors, and ground settlement markers, have been installed around the construction sites. These tools are vital for monitoring any potential risks related to ongoing underground works and nearby structures" said an official.