Weeks after rescue of 41 workers, work begins again at Uttarkashi tunnel

Work on the Silkyara-Barkot tunnel in Uttarkashi, which made headlines on November 12, when one of its sections collapsed, trapping 41 workers who were rescued 17 days later on November 28, has restarted, albeit from the Barkot side of the 4.5km long tunnel, an official from National Highways & Infrastructure Development Corporation Limited (NHIDCL), said.

Read here: Uttarkashi tunnel survivors airlifted to AIIMS-Rishikesh, under medical observation

The collapse happened closer to the Silkyara side — the tunnel itself is part of the larger Char Dham project — and work from that side will begin only after remedial measures on that side, added the official who asked not to be named. The state-owned NHIDCL is overseeing the project that it has contracted out to Hyderabad-based contractor Navayuga Engineering Company Ltd (NECL).

The collapse was caused by a landslide in a zone where the rocks were weak and the remedial measures will likely involve strengthening the area to withstand the tunneling. Once the rescue ended on November 28, NHIDCL was clear that the tunneling would restart, even as it conducted an inquiry and a safety audit into what went wrong.

Anshu Manish Khalkho, director (administration and finance) NHIDCL said then: “One or two accidents don’t stop any process. Everything will go simultaneously; the audit, the inquiry and the project work, which will begin soon.”

However, it will be some time before work starts on the Silkyara side.

Sandeep Sudhera, another official from NHIDCL, said: “We will begin the project work from the Silkyara side. It will be carried out as per proper engineering procedures and site requirement…An Australian designer is working on it.”

A senior official of Rail Vikas Nigam Limited, which is involved in building several tunnels in mountainous regions, detailed the remedial measures required: “They will have to first consolidate the loose mass by grouting…and fill the cavity ... and excavation of the debris can only begin then. They have to be more cautious now to prevent any further incident.”

Naveen Juyal, a geologist who has worked in and studied the Himalayan region, said, “They have to first reassess the complete alignment of the tunnel. The removal of debris on the Silkyara side will be a major challenge. They will have to make sure proper reinforcement along with the removal of debris. If not, there will be further collapse.”

“They have to be extremely careful…they can’t do this task in summer or monsoon. Winters are suitable due to least chances of rainfall,” he added.

A six-member expert committee that was constituted by the Uttarakhand government and which carried out a ground inspection on the cause of the collapse is yet to submit its report.

Shantanu Sarkar, Director of Uttarakhand State Disaster Management Authority Dehradun, said it is in “draft mode” and will be submitted soon. He did not share any details of the findings.

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However, one of the members who spoke on condition of anonymity said: ““The area where the tunnel is being constructed is part of a shear zone that comprises rock mass of poor quality. There was negligence, undoubtedly that led to the incident. If proper support measures had been taken, the incident would have never happened; also, there was no real-time monitoring.”