The phase-2 metro station would be built near the existing facility, Nandanam would become the major underground metro rail interchange. This would allow the commuter to switch corridors seamlessly.
What many people would not know is that at Nadanam boring of the tunnels would be highly challenging due to the presence of rocky soil. Truth is that at places like Kilpauk, Nandanam and 1000 Lights, tunnels of both the phases would meet.
The project director of CMRL, Mr. Arjunan hinted that by 2026 118.9km phase-2 would get ready for use. In these above said places, the phase-2 tunnels would pass under the already present phase-1 tunnels. He added that executing would be very difficult. It is important to bore tunnels without causing problems to the already existing tunnels above. Information is that the tunnels have been planned at a depth of 30m from the ground level.
It is known that at Nadanam the soil is rocky in nature and the existing twin tunnels are present at a depth of 16m.The sensational information is that the new twin tunnels would pass under these in a perpendicular direction with the 2 sets atleast 8m apart.
Soil condition and vibration studies have played a part in deciding the distance between phase 1 and phase 2 tunnel. This was according to Mr. P. Ramanathan, CMRL director. He added that there would be no damage or disturbance to the existing tunnels. He hinted that there are already 2 sets of tunnels one below the other at Central in Chennai.