Chennai Metro Rails TBMs to start tunneling between Thiruvanmiyur and Indira Nagar for section II venture in November

Chennai Metro Rail is all set to start out tunnelling work in probably the most difficult stretches for the upcoming section II venture between Thiruvanmiyur and Indira Nagar in November.

Two tunnel boring machines (TBM) will create twin tunnels for a distance of practically 650 metres between Thiruvanmiyur and Indira Nagar.

In the 118.9 km section II venture, hall 3 from Madhavaram to SIPCOT by way of Adyar whose size is 45.8 km has a good portion of underground community of 26.8 km; one in all them is the Thiruvanmiyur to Indira Nagar stretch. In just a few years, trains originating from Madhavaram will take commuters by way of a minimum of 40 areas together with Thiruvanmiyur and Indira Nagar earlier than reaching SIPCOT.

Officials of Chennai Metro Rail Limited (CMRL)mentioned they’ve been excavating for just a few weeks now at Thiruvanmiyur station website; whereas one of many TBMs have been lowered, the opposite will likely be achieved quickly. 

The main problem now’s excavation of the positioning as a result of presence of onerous rock. “We did count on to come across onerous rock at Thiruvanmiyur however didn’t foresee that it could be such high-quality onerous rock like granite. Initially, the contractor deliberate to hold out managed blasting to interrupt them and full the excavation. But as a greater various, the contractor selected to make use of chemical compounds and disintegrate the onerous rock,” an official mentioned.

CMRL officers added they’re presently excavating at a depth of twenty-two metres at Thiruvanmiyur. Owing to the presence of onerous rock, the tunnelling work too could also be fairly gradual on this 650-metre stretch between Thiruvanmiyur and Indira Nagar. Ideally such a brief stretch will be accomplished quickly, however officers count on that it might take practically a 12 months for the machines to create twin tunnels. 

“If the machine always drills by way of onerous rock, the cutter head discs of the TBM will put on out quickly and we must perform a course of referred to as cutterhead intervention and alter the elements. Cutterhead intervention could should be achieved a number of instances for each machines alongside this stretch and might be time consuming,” an official mentioned.