Click it and Unblock the Notifications
Chennai Metro Rail Limited has recently started tunnelling work between Thiruvanmiyur and Indira Nagar as part of its Phase II metro project. So far, the tunnel boring machine (TBM) has drilled nearly 100 metres into the ground.
Chennai Metro Expansion Project
This work is part of a large ₹63,246 crore expansion project that includes three major corridors across Chennai. These are Corridor 3, Madhavaram to SIPCOT, Corridor 4, Light House to Poonamallee, and Corridor 5, Madhavaram to Sholinganallur. All three routes include both elevated and underground sections and have been under construction for the past few years.
Tunnelling Process for Chennai Metro Corridor 3
For Corridor 3, the underground tunnelling is being done in smaller sections. One such section between Thiruvanmiyur and Indira Nagar has now begun. Officials said that before starting the tunnelling, a deep shaft had to be built at the station site so that the TBM could be lowered underground and launched properly. Once this was completed, the drilling process began.
The stretch between these two locations is about 650 metres long and mainly consists of hard rock. Because of this, a special TBM designed to cut through tough rock is being used. However, the hard geological conditions are expected to slow down the work. Parts of the TBM, such as the cutterhead, may need to be replaced more often than usual.
Time Period for Tunnelling Process Completion
Officials estimate that it may take around six months for the TBM to complete this short stretch. Also, due to space and site limitations, a second TBM can only be launched after the first reaches Indira Nagar.
The project has already faced delays. Earlier, tenders for underground work had to be cancelled because companies quoted very high prices. However, constructing the station shaft was difficult due to the rocky terrain. Instead of blasting, contractors used chemicals to break down the rocks.
