Officials and workers from project owner, Chennai Metro Rail Ltd. (CMRL) and contractor, Tata Projects Ltd have celebrated the breakthrough of the 6.61m diameter S97 Terratec EPBM Podhigai” working on the Package TU-01 contract on the Chennai Metro Rail Phase-II Corridor 3, a 9km twin-tube tunnel (totalling 18km) in India.
Chennai Metro Rail Ltd. awarded Tata Projects Ltd. the Package TU-01 contract back in May 2021, setting a 42-month deadline for completion.
The TBM S97 along with six other TBMs will play a crucial role in the construction of approximately 9km of twin tunnels (totalling 18km) for Corrdior-3 underground section, extending from Venugopal Nagar Station to Kelly’s Station. Terratec is supplying five out of the seven TBMs required for this significant package, and commenced the dispatch of the five TBMs in 2022.
Notably, TBM S96 achieved its breakthrough in August 2023 at Madhavaran High Road, while TBM S98 accomplished its breakthrough in June 2023, moving from the same shaft at Madhavaran Colony towards Venugopal Nagar Station (of Line-5) to Kelly’s Station. TBM S99 also celebrated its breakthrough in September 2023 at Venugopal Nagar Station.
The Chennai Metro Project Phase 2 – Corridor 3, Package – TU01 encompasses various construction tasks, including diaphragm walls and the creation of entry and exit structures for Madhavaram Milk Colony Station, Murari Hospital Station, Ayanavaram Station, and Purasaiwakkam High Road Station. Additionally, the project involves the establishment of launching and retrieval shafts at the aforementioned stations. The project also poses challenges in tunnelling beneath historical structures in densely populated areas.
The Terratec TBMs are equipped with versatile mixed-ground dome-style cutterheads that effectively handle various geological conditions, such as sand, silt, clay, and weathered rock. The TBMs progress with the installation of 1,400mm wide and 275mm thick universal reinforced concrete lining rings, comprising five segments and a key, ensuring stability and structural integrity throughout the tunnelling process.
The rapid population growth and increasing traffic volumes in Chennai have put significant strain on the city’s urban transport system. To address this, the government of Tamil Nadu has undertaken the Chennai Metro Rail Project, providing the people of Chennai with a modern, efficient, and affordable mode of public transportation. The project is scheduled to be completed within a tight timeframe of approximately four years.