Overview:
Efforts are underway to rescue workers at the site of the 4.5 km Silkyara Badkot tunnel, which collapsed on Sunday.
The Landslide Blog is written by Dave Petley, who is widely recognized as a world leader in the study and management of landslides.
In northern India, operations are underway to rescue 40 people who have been trapped in a tunnel that has collapsed in Uttarakhand. The tunnel caved in on Sunday 12 November. The workers are known to be safe, but operations to clear the collapsed debris have proven to be difficult. The Indian Express has a page that is providing updates about what is is clearly a tense operation.
The collapse occurred on a part of the troubled Char Dham road development project, on which I have previously written. The 4.5 km Silkyara Badkot tunnel is on a section of road between Silkyara and Dandalgaon in Uttarkashi district. The location of the tunnel is shown in the Google Earth image below, at about [30.7711, 78.2528]:-
Initial rescue operations have focused on removing the collapsed debris, but have been hampered by further collapses of unsupported materials. The current plan is to drive a 900 mm diameter steel pipe through the debris, allowing the trapped workers to escape.
There are two interesting back stories to this accident. The first relates to the cause of the collapse itself. ANI News has an explanation for what led up to the accident, quoting a report from the National Highways and Infrastructure Development Corporation Ltd. This indicates that the tunnel was being reprofiled in the section that collapsed.
Second is the level of longer term concern about this particular project. SANDRP has an excellent article from 2019 (in Hindi) that raises concerns about this particular tunnel. The article starts:
“This report shows the adverse effects on the local environment and villagers due to disregard for rules in tunnel construction work on Dharasu Band near Barkot”
It highlights that waste from tunnel construction has been dumped into the rivers, whilst poorly controlled blasting and loss of forests have also caused many problems.
The immediate priority is to rescue the trapped workers, of course, which is planned to be completed in the next 24 hours. However, the longer term issue is to improve the quality of construction for the Char Dham project.