Context:

• Several laborers have been trapped after a portion of an under-construction tunnel collapsed in Uttarkashi district of Uttarakhand. 

Under-Construction Uttarakhand Tunnel Collapsed 

• The tunnel is located on the Yamunotri National Highway near Silkyara and was being constructed under the Chardham Highway Project.
• Accident spot located near Main Central Thrust of the Himalayas and this area is extremely sensitive to earthquakes and frictional shear rocks are present in this area.
• Experts raised questions on geological and geotechnical surveys for the project and said that mainly two types of incidents occur during tunnel construction in Uttarakhand — 
  • Sudden release of large amounts of water and 
  • Unexpected encounter of sheared rocks (worn by rubbing against each other). 

Silkyara Bend-Barkot Tunnel in Uttarakhand

• Silkyara Tunnel: It is around a 4.5 Km long two-lane Bi-Directional tunnel with an escape passage on Dharasu –Yamunotri.
• Significance: 
  • This tunnel will provide all-weather connectivity to Yamunotri, encouraging regional socio-economic development, trade, and tourism within the country. 
  • It will reduce the travel distance from Dharasu to Yamunotri by about 20 km and travel time by about an hour.

Char Dham Highway Project

• The project aims to enhance road connectivity and ensure the safety and convenience of pilgrims traveling to Uttarakhand’s 4 major shrines viz. Badrinath, Kedarnath, Gangotri, and Yamunotri.
• The project involved widening and upgrading existing roads, constructing new roads, and implementing measures to make the journey smoother and safer. 

News Source: Down To Earth