{"data":{"news":{"items":[{"title":"Work well underway on 21-km tunnel for MAHSR corridor, including India’s first undersea rail tunnel","date":"2024-03-25 09:00:09","id":5238,"author":"","blurb":"","blurb_image_uid":"https://dxfpracgmlczp.cloudfront.net/2024/03/1711203987821_Undersea Tunnel Graphic-V2.jpg","blurb_expanded_image_uid":null,"article":"\n\t\n\n\n

Work is currently underway on a 21-km-long tunnel in the state of Maharashtra, India, which includes the country’s first undersea rail tunnel featuring approximately 7 km long, as part of the Mumbai-Ahmedabad High Speed Rail (MAHSR) corridor.

\n\n

The tunnel runs between the underground station at Bandra Kurla Complex (BKC) and Shilphata, with the 7-km undersea tunnel at Thane Creek. According to the National High Speed Rail Corporation Limited (NHSRCL), three tunnel boring machines (TBMs) will be deployed to build about 16 km of the tunnel portion and the remaining 5 km will be adopting the New Austrian Tunnelling Method (NATM).

\n\n

The construction work is taking place at several locations:

\n\n

\n\t
Shaft 1 at BKC station construction site in Mumbai (shaft depth of 36 m): The secant piling work has been completed, while the excavation work is ongoing.
\n\t
\n\t
Shaft 2 in Vikhroli (shaft depth of 56 m): The piling work has been completed, while the excavation work is ongoing. This shaft will be used to lower two TBMs in different directions, one towards BKC and the other towards Ghansoli.
\n\t
\n\t
Shaft 3 in Sawli, near Ghansoli (shaft depth of 39 m): The excavation work is ongoing.
\n\t
\n\t
Shilphata: This is the NATM end of the tunnel. The portal work has already begun at the site.
\n\t
\n\t
ADIT (Additionally Driven Intermediate Tunnel) Portal: This portal will facilitate additional access to the underground/undersea tunnel for faster construction progress.
\n\t

\n\n

The shafts are being built in areas with a high population density and adjacent utilities, such as various pipelines, electrical installation and other infrastructure projects like metro systems, highways, etc. Thus the construction work has to be carried out with minimal disruption to the public.

\n\n

To build the 21-km tunnel, which has a diameter of 13.1 m, TBMs with a 13.6-m-diameter cutterhead will be used, said NHSRCL. This single-tube tunnel will accommodate twin tracks for both up and down track. A total of 39 equipment rooms will also be constructed, as part of the package.

\n\n

The tunnel will be about 25- to 57-m-deep from the ground level and the deepest construction point will be 114 m below the Parsik hill.

\n\n

The three shafts at BKC (under package C1), Vikhroli and Sawli at approximate depths of 36, 56 and 39 m respectively will facilitate the construction of the tunnel with TBMs. An inclined shaft of 42 m at Ghansoli and the tunnel portal at Shilphata will facilitate the construction of the approximately 5-km tunnel through the NATM method.

\n\n

All images: National High Speed Rail Corporation Limited

\n\n

Note: This story has also been published in the Mar/Apr 2024 issue of SEAC (with more images). Click here to read online or here to download the PDF file (pages 52-55).

\n\n\n","article_image_uid":"https://dxfpracgmlczp.cloudfront.net/2024/03/1711204001486_Undersea Tunnel Graphic.jpg","article_expanded_image_uid":null,"article_image_caption":"When completed, India’s first undersea rail tunnel will feature approximately 7 km long. It forms part of a 21-km tunnel for the Mumbai-Ahmedabad High Speed Rail (MAHSR) corridor.","publications":"7","tags":"India,railway,tunnelling,tunnel,NHSRCL,MAHSR,high speed rail","category":"Projects"},{"title":"100 km of viaducts completed for Mumbai-Ahmedabad HSR corridor","date":"2023-12-11 00:16:18","id":5015,"author":"","blurb":"","blurb_image_uid":"https://dxfpracgmlczp.cloudfront.net/2023/12/1702124517304_MAHSR construction activity in Navsari District..jpg","blurb_expanded_image_uid":null,"article":"\n\t\n\n\n

Construction of the Mumbai-Ahmedabad High Speed Rail (MAHSR) corridor has achieved a new milestone with the completion of 100 km of viaducts and 250 km of pier work.

\n\n

The viaducts include bridges over six rivers: Par (Valsad district), Purna (Navsari district), Mindhola (Navsari district), Ambika (Navsari district), Auranga (Valsad district) and Venganiya (Navsari district), all located in the state of Gujarat.

\n\n

According to India’s National High Speed Rail Corporation Limited (NHSRCL), these viaducts were built using the full span and span-by-span launching methods. The full span launching method (FSLM) involves launching 40-m-long box girders with state-of-the-art equipment.

\n\n

NHSRCL said the FSLM method is 10 times faster than the span-by-span method, the latter of which is normally used for construction of metro viaducts. The first girder was launched in November 2021 and by April 2023, 50 km of viaducts were already completed.

\n\n

Meanwhile, the laying of the first reinforced concrete (RC) track bed for the MAHSR track system as used in the Japanese Shinkansen has commenced in Surat district. This the first time that the J-slab ballastless track system is being implemented in India, revealed NHSRCL.

\n\n

The MAHSR’s first mountain tunnel of 350 m long has been completed as well, located in Valsad district. In addition, the first steel bridge of 70 m long has been erected in Surat. NHSRCL said there will be a total of 28 steel bridges for the project.

\n\n

When fully completed, the MAHSR corridor will be a game-changer for India, covering a 508 km distance between the cities of Mumbai and Ahmedabad

\n\n

All images: NHSRCL

\n\n

\n\n\n","article_image_uid":"https://dxfpracgmlczp.cloudfront.net/2023/12/1702121684476_MAHSR construction activity in Navsari District.jpg","article_expanded_image_uid":null,"article_image_caption":"The completed viaducts include bridges over six rivers.","publications":"7","tags":"India,railway,NHSRCL,MAHSR,high speed rail","category":"Projects"},{"title":"Afcons wins contract to build India’s first undersea rail tunnel","date":"2023-06-18 12:55:13","id":4694,"author":"","blurb":"","blurb_image_uid":"https://dxfpracgmlczp.cloudfront.net/2023/06/1686978723106_C2 Tunnel Infographic.jpg","blurb_expanded_image_uid":null,"article":"\n\t\n\n\n

India’s National High Speed Rail Corporation Limited (NHSRCL) has awarded a contract to Afcons Infrastructure Limited for the construction of a 21-km-long tunnel in the state of Maharashtra, which includes the country’s first undersea rail tunnel featuring approximately 7 km long, as part of the Mumbai-Ahmedabad High Speed Rail (MAHSR) corridor.

\n\n

The technical bids and financial bids for this tender, the MAHSR C-2 package, were opened on 9 February and 6 April 2023 respectively.

\n\n

“Construction of a 21-km tunnel is one of the most challenging contracts of the Mumbai-Ahmedabad HSR corridor, which includes construction of the country’s first twin-track undersea rail tunnel of 7 km at Thane Creek. Three tunnel boring machines and the New Austrian Tunnelling Method [NATM] will be used for the construction of this tunnel,” said Shri Rajendra Prasad, managing director of NHSRCL.

\n\n

According to NHSRC, the 21-km tunnel will run between the underground station at Bandra-Kurla Complex and Shilphata, with the 7-km undersea rail tunnel at Thane Creek (intertidal zone). It will be a single-tube tunnel to accommodate twin tracks for both up and down track. A total of 39 equipment rooms at 37 locations will also be constructed, as part of the package.

\n\n

The tunnel will be around 25- to 65-m-deep from the ground level. Three tunnel boring machines (TBMs) will be deployed to create about 16 km of the tunnel portion, while the remaining 5 km will be built using the NATM method.

\n\n

To construct this tunnel, TBMs with a cutterhead diameter of 13.1 m will be adopted, which NHSRCL said is quite different from the 5- to 6-m-diameter cutterheads normally used for urban tunnels in the MRTS – Metro system.

\n\n

NHSRCL further revealed that three shafts at BKC (under package C1), Vikhroli and Sawli at approximate depths of 36, 56 and 39 m respectively will facilitate the construction of the project. An inclined shaft of 42 m at Ghansoli and a tunnel portal at Shilphata will facilitate the construction of the approximately 5-km tunnel.

\n\n

All images: NHSRCL

\n\n\n","article_image_uid":"https://dxfpracgmlczp.cloudfront.net/2023/06/1686978660122_Image.jpg","article_expanded_image_uid":null,"article_image_caption":"The contract signing ceremony between NHSRCL and Afcons Infrastructure.","publications":"7","tags":"India,railway,tunnel,Afcons Infrastructure,NHSRCL,MAHSR,undersea","category":"Projects"}],"pageInfo":{"hasNextPage":false,"hasPreviousPage":false,"totalCount":3,"totalPages":0,"currentIndex":0}}}}