TBM Kaveri achieves tunnel breakthrough at Adyar Junction for Chennai Metro Phase 2

Chennai, India (Metro Rail Today): Chennai Metro Rail Limited (CMRL) is making significant strides in the much-anticipated Phase 2 project, which will expand the metro network across Chennai City. This expansion includes three corridors totaling 116.1 kilometers, aimed at enhancing urban mobility and reducing congestion.

The tunneling works for Corridor 3, connecting Greenways Station to Adyar Junction Station, commenced in February 2023. Each tunnel stretches approximately 1,228 meters and passes beneath the Adyar River for a substantial 300 meters, with an overburden of 10 to 13 meters. This challenging engineering feat highlights the ambitious scope of the Phase 2 project.

Among the key players in this tunneling operation are two Earth Pressure Balancing (EPB) Tunnel Boring Machines (TBMs), named ‘Kaveri’ and ‘Adyar.’ Recently, TBM Kaveri successfully completed its tunnel drive and achieved a breakthrough at the Adyar shaft. This remarkable accomplishment is a testament to the TBM's capability to navigate through mixed geological conditions, including hard rock and sand, below various urban structures.

The journey of TBM Kaveri has not been without challenges. The machine encountered hard rock formations below parts of the Adyar River and underwent 65 cutter head interventions to replace its cutting tools. In total, this process consumed 178 days, underscoring the complexities involved in urban tunneling.

During its operation, TBM Kaveri traversed beneath several significant landmarks, including:

• Petrol bunks
• MGR Janaki College
• Andhra Sabha Hospital
• Durgabai Deshmukh Road
• Adyar Bridge Ramp

This intricate path reflects the careful planning and engineering expertise required to minimize disruptions in a densely populated urban environment.

Currently, the second TBM, named ‘Adyar,’ is 277 meters away from the Adyar shaft, with expectations to reach its destination by November 2024. The successful operation of both TBMs is crucial for meeting the project timelines and ensuring the efficient construction of the metro network.

The breakthrough achieved by TBM Kaveri at Adyar Junction Station marks a pivotal moment in Chennai’s metro expansion. As CMRL continues to advance the Phase 2 project, the successful operation of the TBMs showcases the engineering prowess and dedication required to enhance public transport in Chennai. With the metro network set to expand significantly, the project promises to improve urban mobility and contribute to the city’s sustainable development goals.