Uttarakhand tunnel collapse: Experts flag urgent need for advanced geological surveys

As many as 41 workers are still stuck in an under-construction tunnel in Uttarkashi, part of the Char Dham project, after a portion of the tunnel collapsed due to a landslide. As hilly areas are prone to landslides and subsidence, this incident highlights the unique challenges in such terrains. 

A thorough geological and geotechnical survey is essential to assess terrain stability and identify potential landslide and erosion risks. This forms the basis for ensuring structural integrity in uneven landscapes, with the implementation of slope stabilisation measures tailored to the specific slope and rock structure sequencing. Additionally, the construction plan should incorporate effective drainage systems and erosion control strategies to mitigate damage from heavy rainfall, taking into account subsurface water and nearby streams.

Vikramjiet Roy, Managing Director, Maccaferri (In India), a company that provides tailor-made design and development solutions for complex civil, geotechnical and environmental engineering projects, says, “In hilly terrain, planning authorities must conduct comprehensive site assessments to understand geological stability, soil quality, and potential natural hazards like landslides. Specialised foundation designs, such as pile foundations and retaining walls, are often needed due to the uneven and steep landscape,” adds Roy. Techniques like soil nailing and rock bolting ensure slope stability. Additionally, minimising environmental impact and controlling water runoff are crucial in ecologically sensitive areas.

Moreover, Roy adds that disaster preparedness, particularly early warning systems, is crucial, especially in regions susceptible to seismic activity and other natural disasters. Engaging local communities in decision-making processes helps foster acceptance and minimises social conflicts. Efficient resource management, worker safety measures, long-term maintenance strategies, and compliance with government regulations are all essential in constructing safely and sustainably in hilly terrains.

Also, the detailed project reports (DPR) prepared for the projects should consider the latest available technologies. The DPR should be prepared based on relevant data and considerations. For example, the drainage channels, river bank protections shall be designed considering flood of 100 year return period. Simulation of floods shall be carried out considering the proposed development and accordingly protection measures shall be planned. The DPR consultant shall be chosen based on relevant experience of using latest tools and not just L1 (Least Cost Selection Method) criteria.

Given the infrastructure that is being built in the India currently, Roy complements the government, saying there is scope for more collaborative work between the government and experts to make substantial progress in fragile areas. “The decision of the Supreme Court to establish a panel to study environmental and ecological concerns in overcrowded hill stations across Uttarakhand, Himachal Pradesh, and other Himalayan states is a significant step in the right direction.”

Sharing his insights and expertise, Roy shares that to build on these efforts, it is crucial for the government to invest in comprehensive geological surveys and mapping to identify high-risk areas susceptible to landslides and other geological hazards. This data should inform zoning regulations and urban planning to restrict construction in vulnerable zones, ultimately minimising risks.

Also Read: Uttarakhand  tunnel collapse: All eyes on Hyderabad-based Navayuga Engineering