Bids have been invited for India’s first undersea tunnel, which will be a part of the Mumbai-Ahmedabad bullet train corridor being built by the National High Speed Rail Corporation Limited (NHSRCL).
The underground tunnel would be 21km long from Bandra Kurla Complex to Kalyan Shilphata in Maharashtra. The tunnel would have 1.8km built on the sea bed, 7km under the Thane creek and the remaining would be built under mangroves on either side of the creek. The total length of the corridor from Mumbai to Ahmedabad would be 508km.
The tender was issued for the construction of the tunnel as well as testing and commissioning for double line high-speed railway using tunnel boring machine (TBM) and new Austrian tunnelling method (NATM) for the project. Bids can be submitted at the NHSRCL office from 26th April to 22nd August this year, and the Technical Bid will be opened on 23rd August in the presence of representatives of the bidders. A pre-bid meeting has also be organised on 24th May for the eligible bidders/
The project is to be completed in 1,280 days or 3.5 years. A geo-technical investigation of the undersea tunnel area was conducted last year by a team of engineers from NHSRCL, RITES Ltd and Japan’s Kawasaki Geological Engineering. To determine the density of the rock under the sea bed, a survey was done by using static refraction technique (SRT) to study the sea bed. The final report was submitted last year.
Apex institutes like Zoological Survey of India (ZSI), Mangroves Survey of India (MSI), National Institute of Oceanography (NIO) have studied the environmental impact of the project area and have given environment clearance for the project claimed NHSRCL.
“ZSI in their report have stated that there is minimal disturbance to the wildlife in this region. No mangroves will be cut in this area as it will be an undersea/underground tunnel 20-40 meters below the ground/sea level,” said Sushma Gaur, NHSRCL spokesperson.