Chennai Metro Rail Limited (CMRL) has marked a significant milestone with the successful completion of a 903-metre tunnel between Ayanavaram and Otteri. The tunnel boring machine (TBM) Kolli, designated as S 81, achieved this feat on August 29, 2024, following its initial operation which began on July 11, 2023.
This completion represents the sixth successful breakthrough for Tata Projects Limited under the TU-01 contract and contributes to the total of seven TBM breakthroughs in CMRL’s Phase-2 project. The Ayanavaram to Otteri section presented substantial engineering challenges. Notably, the first 500 metres of the tunnel required navigating a sharp 220-metre radius curve, while the final 200 metres encountered a 280-metre radius curve. Additionally, the tunnelling had to be conducted in densely populated areas and manage over 100 bore wells. This complex undertaking necessitated meticulous planning to ensure minimal disruption to existing water sources and surrounding infrastructure. The entire process was closely monitored to maintain ground stability and safeguard the areas above the tunnel.
The completion of this tunnel section underscores the advanced capabilities and resilience of the Chennai Metro Phase-2 expansion project. As the CMRL continues to push forward with its ambitious infrastructure goals, the successful deployment of TBM Kolli highlights the project’s progress and the effective management of its challenging aspects. This achievement not only marks a technical triumph but also reinforces the ongoing commitment to enhancing urban mobility in Chennai.
