Express News Service
CHENNAI: The tunnelling work of Chennai Metro Rail Limited’s Phase-II project between Madhavaram to Kellys, which is passing through densely populated areas is progressing smoothly with 200m of work already finished, said Rahul Shah President and COO – Buildings and Infrastructure – Tata Projects.
The work in the Corridor-3 of the second phase of the Chennai Metro Project involves the construction of nine-km twin bored tunnels, totalling 18-km from tunnel boring machines (TBMs) retrieval shaft near Venugopal Nagar to Kellys Station and the construction of diaphragm walls of station box and entry and exit structures of Madhavaram Milk Colony, Murari Hospital, Ayanavaram and Purasaiwakkam High Road Stations, including launching and retrieval shafts as required.
“Currently, two tunnel boring machines are being used. We are planning to use two more machines this month and the remaining three tunnel-boring machines in the stretch by April. On a whole, a total of seven tunnel boring machines will be used to complete the 9-km stretch,” said Shah.
Corridor-3, a North-South line from Madhavaram to SIPCOT, would be 45.8 km in length with 50 stations, of which 20 would be elevated and 30, underground and link prime locations like the IT Corridor, Adyar, Mylapore and Purasaiwalkam.
Shah said the stretch passes through dense and populated areas, including Perambur, Ayanavaram and Purusaiwalkam and that is why the underground stretch is chosen for the project. “We are taking care that the structures on the surface are not disturbed during the tunnel boring operation. We are also monitoring the vibrations 30m below. In some cases, we have to strengthen the structures before the TBM approaches the structure,” he said.
Most of the work is being carried out during the night and we are planning to complete the project in the next 18 to 24 months. “Some of the stations to be built are not under our scope. Of the 13 stations, a total of nine stations are yet to be tendered,” said Shah.
Tata Projects is using German trench-cutting technology for the first time. “We are using four trench cutters imported from Germany. The technology is ideal for the geological formations in Chennai.
He also said the tunnelling expertise has been gained in India in the last 10 years with underground metro projects being taken up across the country. “Initially, we were reliant on southeast Asia for the tunnel technology. Now India has the expertise to operate and maintain the machines,” said Shah.