Major Milestone Achieved: 394-meter-long ADIT Completed for Mumbai-Ahmedabad Bullet Train Project
In a significant stride towards the Mumbai-Ahmedabad Bullet Train Project, the Additionally Driven Intermediate Tunnel (ADIT) spanning 394 meters at Ghansoli has been successfully excavated. This accomplishment marks a crucial step forward in expediting the construction of the 21 km long tunnel connecting Bandra-Kurla Complex (BKC) and Shilphata in Maharashtra.
The ADIT, with a depth of 26 meters, plays a pivotal role in facilitating the construction process through the New Austrian Tunnelling Method (NATM). It enables simultaneous access for tunnelling on each side, allowing for efficient progress. Out of the total 21 km of tunneling works required, 16 km will be undertaken using Tunnel Boring Machines (TBMs), while the remaining 5 km will utilize the NATM.
Excavation work for the ADIT commenced on December 6th, 2023, and the entire length of 394 meters was completed within a remarkably short span of six months. A total of 214 controlled blasts, employing 27,515 kg of explosives, were meticulously executed under expert supervision, ensuring the safety of the excavation process.
The ADIT, boasting internal dimensions of 11 meters by 6.4 meters, not only provides direct vehicular access to the main tunnel during construction and operations but also serves as a potential evacuation route in emergency situations.
To ensure the safety and integrity of the tunnel and surrounding structures, a comprehensive array of monitoring instruments is being deployed. These instruments include Surface Settlement Points (SSP), Optical Displacement Sensors (ODS), By Reflect Target (BRT) systems, Strain Gauges, and Seismographs.
Meanwhile, construction activities for the 21 km long tunnel from the Mumbai Bullet Train station to Shilphata are progressing rapidly. Notably, a 7 km stretch of this tunnel will traverse beneath the sea at Thane Creek, marking a pioneering endeavor in the country’s infrastructure landscape.
The tunnel, designed as a single tube to accommodate two tracks for up and down trains, represents a groundbreaking engineering feat. Tunnel Boring Machines (TBMs) with cutter heads boasting a diameter of 13.6 meters are being employed for its construction, underscoring the scale and complexity of the project.
Furthermore, the ongoing construction of three shafts at strategic locations – BKC, Vikhroli, and Sawli – will facilitate the tunneling process through TBMs, further streamlining the project’s execution and ensuring its timely completion.
