Come September, a significant milestone will be achieved in Chennai’s metro expansion project. The ambitious plan involves tunnelling under the Adyar River near the Greenways Road metro station, marking a significant engineering feat. Let’s delve into the details of this remarkable endeavor.
Project Commencement and Progress
The tunnel boring machine (TBM), aptly named Kaveri, initiated its excavation journey beneath the RA Puram corporation playground back in February. As of now, the TBM has covered a distance of 120 meters and is approaching the riverbed.
Anticipated to begin in September, the TBM will delve 20 meters below the river’s surface to start boring a 400-meter-long tunnel. This tunnel will ultimately connect the Greenways Road metro station with the Adyar junction station, creating a seamless travel experience for commuters.
Challenges and Considerations
The meticulous planning of this project takes into account a range of challenges. Notably, the tunnel’s construction beneath a water body poses unique difficulties, particularly regarding water pressure. The tunnel wall, which will be approximately 35cm thick, is designed to withstand varying levels of pressure. If required, the thickness may be increased to 40cm or 45cm to ensure the tunnel’s integrity.
Furthermore, the tunnel boring process involves waterproofing to prevent any water seepage. This is achieved by meticulously sealing gaps between tunnel segments and rings, safeguarding against potential leaks.
Experts acknowledge that the TBM’s pace may slow down as it ventures beneath the riverbed, potentially reaching a speed of 1 meter per day. This cautious approach is essential to maintain the stability of the surrounding structures and prevent any inadvertent damage.
Once complete, the tunnel will extend over a distance of 1.2 km, providing an essential link between the Greenways Road metro station and the Adyar junction station. This segment forms a crucial part of the larger 45.4 km corridor-3, connecting Madhavaram Milk Colony to Siruseri Sipcot.
The broader vision for Chennai’s metro expansion is equally promising. Phase 2, spanning 116.1 km, is anticipated to open in stages between 2025 and 2028, significantly enhancing the city’s public transportation infrastructure. Additionally, the project includes the construction of tunnels under the Chetpet lake, showcasing the city’s commitment to innovative and sustainable urban development.
The Adyar River tunneling project stands as a testament to Chennai’s ambition and engineering prowess. As the TBM delves beneath the river’s depths, it ushers in a new era of connectivity and accessibility for the city’s residents. With careful planning, meticulous execution, and a commitment to overcoming challenges, this remarkable feat of engineering promises a brighter, more connected future for Chennai.