Tunnelling by New Austrian Tunneling Method (NATM ) commenced on 6 February at the south end of BKC Station for the 153m long tunnel below Mithi River. (@MumbaiMetro3/twitter)The Mumbai Metro Rail Cooperation (MMRC), has begun tunnelling a 153 meters long tunnel below the Mithi river.
The 153-metre long tunnel is dug using the New Australian Tunnelling Method (NATM) between Dharavi and Bandra-Kurla Complex (BKC). The proposed BKC station will be underwater, and the works are expected to be completed by August 2020.
The 33.5 km Metro 3 line will reportedly be the second Metro in the country to have tunnels under the riverbed, where the first was constructed under Hooghly river in Kolkata, reported Times of India.
“The BKC Metro station, that will come up below Mithi river will have two island platforms instead of one island platforms as is being constructed at the other 25 underground stations,” S K Gupta, MMRC Director (Projects) was quoted saying by TOI.
According to the report, the BKC station would be crucial intersection point as it is being designed as a three-line station with two main platforms and a cross-over line, which will connect to either side of the mainline.
The MMRC had reportedly carried out extensive study and detailed planning before tunnelling beneath the water body.
“The presence of soil and weak rock under the riverbed increases the risk of instability of the excavated opening before proper support is installed,” said Gupta.
Layers of soil and broken rocks under the riverbed will be strengthened by grouting to reduce permeability and the ingress of water. An ‘umbrella’ of steel bars will be created above the excavation area for safety, and there will be a constant check on the soil/rocks during excavation, the TOI report quoted MMRC officials saying.
Also Watch: Mumbai’s First Underground Metro Project Achieves Successful Tunnel Breakthrough
An Appeal...
Dear Reader,
As you are no doubt aware, Swarajya is a media product that is directly dependent on support from its readers in the form of subscriptions. We do not have the muscle and backing of a large media conglomerate nor are we playing for the large advertisement sweep-stake.
Our business model is you and your subscription. And in challenging times like these, we need your support now more than ever.
We deliver over 10 - 15 high quality articles with expert insights and views. From 7AM in the morning to 10PM late night we operate to ensure you, the reader, get to see what is just right.
Becoming a Patron or a subscriber for as little as Rs 1200/year is the best way you can support our efforts.