CMRL phase-2: TBM Kolli tunnels through more than 900 metres at Otteri
The TBM built a tunnel for around 903 metres long, which is part of the first 9 km underground section of corridor 3 from Madhavaram Milk Colony to Kellys.
TBM Kolli completes 903 m tunnel drive from Ayanavaram to Otteri metro stations
CHENNAI: Tunnel Boring Machine (TBM) Kolli achieved a breakthrough at Otteri on Saturday after it began tunnelling from Ayanavaram in July 2023, the Chennai Metro Rail Limited (CMRL) said in a statement on Friday. This marks a milestone in the expansion of the Phase II project.
TBM Kolli (S-81) commenced tunnelling work on Route 3 on July 11 last year at the Ayanavaram Metro Rail Station and completed 903 meters of tunnel work and broke through at the Otteri shaft yesterday.
Route 3 will cover the first 9 km from Madhavaram Dairy to Kellis.
The tunnel construction work for the length is being executed by Tata Projects, and 7 tunnel boring machines are being used for this purpose.
So far, six tunnels have been completed by Tata Projects under contract TU-01.
In total, CMRL has achieved 7 TBM breakthroughs in the Phase-2 project.
The tunnel section between Ayanavaram and Otteri is the most complex tunnel section, in which the first 500-meter tunnelling run with a sharp 220 m radius curve and the last 200 m tunnel run with 280 m radius curves were completed by TBM Kolli, the CMRL said.
Also, the tunnel drive was completed despite challenges such as passing through densely populated areas and over 100 bore wells along the alignment by providing alternate sources without any issue to the public. “The complete drive was managed within the allowable minimum settlements. Extensive instrumentation and monitoring were both ensured throughout the drive,” added the release.
The two stations are part of the 45.4-km corridor-3 from Madhavaram to Siruseri Sipcot in phase-2, which runs a total distance of 116.1 km.
(With inputs from Online Desk and Bureau)
