Major milestone achieved in USBRL Project: 3,209 m long Katra-Reasi tunnel completed
Dec 21, 2023
Jammu and Kashmir [India], December 21 : In a significant breakthrough for the Udhampur-Baramulla Rail Link (USBRL) project, the 3,209 m long tunnel T-1 between Katra and Reasi Stations has been completed.
The project that was completed on Wednesday (December 20) marks a monumental stride towards progress and enhanced connectivity.
Tunnel T-1 is located at the foothills of the Trikuta Hills near Katra in Reasi District and is being constructed by Konkan Railway Corporation Ltd for the Northern Railway under the National Projects.
Under the USBRL project, this breakthrough is a key milestone, ensuring that all tunnels required for the project have been successfully constructed.
The Katra-Reasi stretch, covering a challenging 111 kilometres, faced multiple interruptions during construction, necessitating the involvement of global experts. Tunnel T-1, formerly recognised as the most challenging tunnel due to its passage through the Himalayan Main Boundary Thrust (MBT), presented formidable geological challenges, including rugged terrain and substantial water inflow from within the tunnel.
The tunnel alignment cuts across the lesser Himalayas and is characterised by highly jointed and fractured dolomite.
Also, a portion of about 300-350m length cuts across a major Shear Zone known as the Main Boundary Thrust (MBT). Due to the presence of a shear zone coupled with a high ingress of water, tunnel excavation in this stretch has been a daunting challenge.
In the beginning, the tunnelling was done by adopting the conventional NATM tunnelling philosophy.
However, to tackle the visco-elastic plastic media of the Main Boundary Thrust, the tunnel excavation methodology was switched over from NATM to I-System of Tunnelling by providing deep drainage pipes, Umbrella pipe roofing, chemical grouting, face bolting, sequential excavation with multiple drifts, rigid support and concreting, etc.
By adopting the I-System of tunnelling, the excavation of Tunnel T1 through MBT (in Heading) has been completed, thus clearing a major impediment in the commissioning of the new railway line from Katra to Banihal.
The breakthrough of this tunnel is seen as one of the biggest achievements of this national project in making the dream of connecting Kashmir Valley with the rest of India a reality.
The completion of this tunnel is a significant achievement in the broader context of the USBRL project, which involves the construction of 38 tunnels between Katra and Banihal.
While all tunnels on this rail route have been completed, Tunnel T-1 posed the greatest obstacle, being the longest and encountering unique geological complexities.
The project involved meticulous planning and the application of various engineering technologies, ensuring that the 3209 m long tunnel T-1 is now successfully excavated, underscoring the commitment of Indian Railways to infrastructural progress.
As of today, about 318 m of excavation in benching and about 680m of concrete lining is balanced.
The works are in progress around the clock in full swing to complete the balance works. Indian Railway is edging closer to connecting Kashmir Valley to the rest of the railway network.
