Silkyara-Barkot Tunnel: Concerns Over Safety Were Flagged

New Delhi:Following the rescue of the 41 workers from the collapsed Silkyara-Barkot tunnel in Uttarakhand, concerning details and lapses around the project have been reported by The Indian Express.

Reportedly, the lack of attention to flagged concerns and the absence of an escape tunnel have raised serious doubts about the project, which was under construction when it collapsed.

The National Highways & Infrastructure Development Corporation Ltd (NHIDCL), under the Ministry of Road Transport & Highways (MoRTH), initiated this tunnel project in 2017. Technocrats Advisory Services Pvt Ltd (TASPL), tasked with preparing the Detailed Project Report (DPR), submitted two crucial reports highlighting several warnings.

TASPL's reports detailed the rock types expected during excavation, foreseeing 20% good (Class II), 50% fair (Class III), 15% poor (Class IV), and 15% very poor (Class V) quality rock. It stressed that certain segments of the tunnel alignment were "very unfavourable," potentially causing wedges and instability in the tunnel walls and ceiling during construction.

Moreover, the issue of escape tunnels arises. Union Highways Minister Nitin Gadkari had mentioned in the Rajya Sabha the provision of a "separation wall" with "egress openings" for vehicles and pedestrians in the project. However, the original project plan did not incorporate dedicated escape tunnels, The Indian Express reported.

A senior project engineer, speaking to the newspaper anonymously, justified the absence of the escape tunnel, citing a decision to create more space for traffic by altering the project design at the construction stage.

The geotechnical report advised several support measures like pipe roof umbrellas, pressure grouting, and fully-grouted rock bolts, emphasising a strict excavation sequence and support system installation after each 750-1000 mm cycle.

However, when the tunnel partly collapsed on November 12, nearly 90% of the 4.5-km alignment had already been excavated from both sides, according to The Indian Express. In this regard, a TASPL official noted that the said reports are done by consultants they hire for projects. Hence, in this case, the supervision of provisions being followed during excavation fell on the Hyderabad-based contractor Navayuga Engineering and its German advisor, Bernard Grouppe. It was supervised by TPF Getinsa Euroestudios SL of Spain and New Delhi-based Rodic Consultants under the implementing agency NHIDCL, as per the newspaper.

However, in August this year, the Bernard Grouppe had also flagged dangers around the project. “Since the start of tunnel driving, the geological conditions have proved to be more challenging than predicted in the tender documents, thus confirming the results of the further exploration measures carried out at the beginning of the execution phase,” the advisor said in a note quoted by The Indian Express.

The Silkyara-Barkot tunnel project oversight responsibilities lay with TPF Getinsa Euroestudios SL (Spain) and Rodic Consultants Pvt Ltd (New Delhi) as the project’s Authority Engineer, tasked with monitoring excavation, reviewing designs, quality assurance, and ensuring timely completion. Notably, TPF Getinsa Euroestudios SL, a part of TPF SA of Belgium, has worked before in India through its subsidiary S N Bhobe & Associates Private Limited. However, the subsidiary is linked to a previous incident regarding a flyover collapse in Surat due to design flaws.