Uttarkashi tunnel mishap: No cause for worry as far as Zojila tunnel in J&K is concerned, say project engineers

Zojila pass is situated on the Srinagar-Kargil-Leh National Highway

While the recent tunnel collapse in Uttarkashi has sent alarm bells across the country, is there any cause of concern for Zojila tunnel, another under-construction tunnel in the rugged terrain of the Himalayas, in J&K?

No, say Mehraj Ud Din Lone, associate manager, Geology, Megha Engineering and Infrastructure Limited (MEIL) and Irshad Hussain, Zojila tunnel’s safety officer.

One of the factors they cite is the rock quality. "The superior rock quality within and outside the tunnel makes Zojila risk- free and less vulnerable to any type of incidents. The rock quality in Kashmir can be classified as falling into a good and fair category," said Hussain.

Though progress has been hampered in avalanche-prone areas, leading to multiple work stoppages, the chances of a tunnel collapse are slim, Lone said.

'Ground behaviour can be known beforehand'

"Every day, our staff, who include geo-technical engineers and geologists, monitor the ground and its behaviour with geotechnical instrumentation and 3D monitoring. Such is the technology that we are able to know the ground behaviour and movement beforehand. Also, since the zone is ecologically fragile, we are using an advanced technology -- the New Austrian Tunneling Method (NATM) -- for the construction of the tunnel," he said.

The recent tunnel collapse in Uttarkashi has raised concerns over safety measures in Zojila tunnel, touted as Asia's longest bi-directional tunnel and India's longest road tunnel, in Jammu and Kashmir (J&K).

Burhan Andrabi, liaison officer, MEIL told Moneycontrol that NATM is considered the safest among all the tunnelling methods, and is widely used in North America.

"Tunnel mishaps sometimes happen when engineers and workers do not follow the design. The designers decide the support system while evaluating the rock quality. Each rock is classified by designers and the support system is decided accordingly. When the project team follows the exact design and drawing, the chance of any mishap becomes negligible,” Andrabi explained.

As far as the Zojila tunnel is concerned, Lone said the tunnel is being executed according to a design approved by Spanish-based designers.

Difference in rock system

After excavation, engineers encountered four types of rocks in Zojila, and they are mostly of good and fair quality, Lone said.

The incident has sent alarm bells across the country, and, now, major safety concerns are being raised about the Zojila tunnel, another under-construction tunnel in the rugged terrain of the Himalayas in J&K.

"The support system, which compensates incoming stress, is the key, if the rock quality is average or below average. Uttarakhand does not have a good rock condition. This is why the support system becomes vital in such regions. The rock competency can minimise the risk of the tunnel collapse and when the ground is weak, increased support system is needed," he said.

Engineers also claimed that despite the tunnel location falling into seismic zone IV, a very high risk zone in terms of vulnerability to earthquakes, better rock quality, adherence to procedures and proper monitoring by geologists ensured that the chances of any mishap in Zojila is zero.

Safety features

Hussain said that once MEIL completes the tunnel, it will be equipped with advanced European safety measures, including a fully transverse ventilation system, CCTV monitoring, uninterrupted power supply, emergency lighting, variable message signs, traffic logging equipment, automatic fire detectors, fire alarm buttons, centralised control room, and a tunnel radio system.

"Workers are provided safety gear and special jackets as when blasting is done, the temperature inside the tunnel increases. The specialised staff in the tunnel also monitor the oxygen level and other parameters," he said.

So far, seven workers, mostly locals working on Zojila, have lost their lives mainly due to the avalanche and harsh weather.

"The Himalayas are the world's youngest mountains but they are tectonically active. It is not easy to do tunnelling in the Himalayas because you never know what you will encounter after 1 metre," Lone explained.
For example, last year, due to heavy snowfall and avalanches, the administration ordered closure of work for two months.

So far, eight workers have lost their lives due to various reasons, mainly harsh weather.

Around 2,500 people, including engineers and workers, are involved in the construction now.

Lone told Moneycontrol that the project site starts from Sonamarg in Ganderbal district of Kashmir and ends at Minamarg in Ladakh.

"Part 1 of the project includes a 16-km road to the tunnel, 4 bridges, two small approach tunnels, besides avalanche protection structures, catch dams, snow gallery, cut and covers, and delection dams is almost 75 percent complete. However, part 2, which includes the main tunnel and its excavation work, is 25 percent complete," he said.

Significance of the Zojila pass and tunnel

Zojila pass is situated on the Srinagar-Kargil-Leh National Highway, which remains closed during winter (December-April) due to heavy snowfall and avalanches which cut off Ladakh region from the Kashmir Valley.

The Zojila tunnel, being constructed at one of the most dangerous motorable stretches in the world and at a geo-strategically sensitive location, is expected to provide all-weather connectivity between Kashmir and Ladakh throughout the year.

The foundation stone of the tunnel was laid in 2018, after the approval of the Cabinet Committee on Economic Affairs, led by Prime Minister Narendra Modi.

Work on the project started on October 15, 2020, after the end of the first COVID-19 wave.

The harsh weather conditions in the Himalayas and the tunnel’s location at 11,578 feet above sea level make it a daunting task for workers and engineers to construct the Rs 4,509-crore tunnel project.

Braving all the vagaries of weather and tough terrain, the workers labour even under freezing temperatures, ranging between minus 15 to minus 20 centigrade, to make sure that the 13.1-km-long tunnel is completed well before the deadline of September 2026.

The tunnel will reduce the time to cross the Zojila pass from four hours to just 15 minutes, engineers say.