The Indian Railway has taken up major tunnelling work for broad gauge Third Line between Barkhera-Budni (26.50 km) section of Bhopal-Itarsi Third Line project of the West Central Railway zone.
The Indian Railways’ public sector undertakings (PSU), Rail Vikas Nigam (RVNL), is constructing five tunnels with New Austrian Tunneling Method (NATM) having ballastless track in connection with third electrified broad-gauge railway line between Barkhera-Budni on Bhopal-Itarsi route on Bhopal Division of West Central Railway in Sehore and Raisen Districts of Madhya Pradesh.
This will ease congestion on Golden Diagonal, Delhi-Chennai route. With the commissioning of third line, trains shall run at a speed of 130 km per hour between Bina-Bhopal-Itarsi section.
For capacity enhancement, work of construction of third line on Bhopal-Itarsi section is sanctioned by the railway board in three separate works.
This includes Habibganj (HBJ)-Barkhera (BKA) of 41.42 km for which work is completed; Barkhera (BKA)-Budni (BNI) of 26.5 km for which work is in progress and Budni (BNI)- Itarsi (ET) of 25 km for which work has been completed.
Section-1 and -3 fall in plain territory and do not involve issues such as wildlife/forest clearances, land acquisition, etc.
In Section-2 i.e. Barkhera (BKA)-Budni (BNI) section, the entire length of the existing two tracks as well as the proposed track falls either in Ratapani Wildlife Sanctuary (tiger habitat) or is an eco-sensitive zone.
The Barkhera-Budni Third Line project was sanctioned in the year 2011-12. The cost of the project is Rs 991.60 crore. The project is expected to be completed by June 2022.
RVNL is constructing these tunnels in horseshoe section; this form consists of a semi-circular roof together with arched sides and a curved invert. NATM is a support method to stabilise the tunnel perimeter by means of sprayed concrete, anchors and other supports and uses monitoring to control stability.
The total length of the five tunnels -- T1 (Budni), T2 (Midghat), T3 (Bhimkoti), T4 (Choka) and T5 (Barkhera) is 2,150.00 mtr.
The breakthrough of Tunnel-1 was done on 18 March 2021 and at present invert cleaning and PCC work, installation of 160 mm diameter perforated side drain with Nofine concrete, and invert lining (Bottom RCC) is in progress. For Tunnel-2, portal development work and epoxy grouting in the existing tunnel is in progress. Underground excavation around 51 mtr from Portal-1 and Portal-2 has been completed for Tunnel-3. At present benching excavation in progress from Portel-2 side.
Portal development work is in progress at Itarsi-end for Tunnel-4. Tunnel excavation started from Bhopal-end of 12 mtr excavation has been completed.
Complete excavation by heading and benching of double track for Tunnel T-5 was completed on 9 May 2021. Apart from this, invert cleaning and PCC work, excavation and installation for 315 mm diameter central drain, waterproofing installation and invert lining (Bottom RCC) is in progress.