There are lots of tales behind the 4.89-km-long, eight-lane tunnel on the Delhi-Mumbai Expressway that cuts by means of Mukundra Hills in Rajasthan’s Kota.
Considered one of them is that of 58-year-old Madhukar, who has constructed tunnels all his life. He began this undertaking throughout Covid in 2021 on the north finish, in what might effectively be his final task earlier than retirement in two years. Now, confronted with a tough 500m stretch — he calls it the “nala portion” — Madhukar is set to finish his ninth undertaking efficiently, and will get emotional whereas recounting his affiliation with the tunnel.
The tunnel, which falls between Ummedpura and Nayagaon village in Kota, is a key hyperlink of the Delhi-Mumbai Expressway — one of the crucial formidable tasks of the Nationwide Freeway Authority of India (NHAI) below the Bharatmala Pariyojna. With a width of twenty-two metres and a peak of 11 metres, it’s also one of many widest tunnels within the nation, passing by means of totally different rock lots and substrata that embody sandstone, shale, siltstone, mudstone and limestone.
Within the undertaking cluster, which is split into 53 packages, the Ummedpura-Nayagaon tunnel is being constructed by a three way partnership of Dilip Buildcon Restricted and Altis-Holding Company. It was initially a 30-month undertaking scheduled to be accomplished in January 2024, however bought delayed as a consequence of challenges throughout excavation and is now more likely to be accomplished by the year-end.
“Hum rock se dosti karte hain, aap rock se dushmani karke tunnel nahi bana sakte (We befriend the rock, you possibly can’t make a tunnel by combating with the rock). On this undertaking additionally, now we have come to probably the most tough half, however we are going to move it slowly. Now we have to only perceive the behaviour of the rock,” stated Madhukar, a resident of Khagaria in Bihar, who’s in command of the blasting.
The tunnel passes by means of totally different rock lots and substrata that embody sandstone, shale, siltstone, mudstone and limestone. (Specific photograph by Dheeraj Mishra)
Having labored in tough terrains throughout Sikkim, Uttarakhand, Mizoram and Himachal Pradesh, Madhukar, who holds a diploma in mining, deconstructs the problem. “The highest floor of the hill is in a zig-zag form. Now we have come to a degree the place the gap between the highest of the tunnel and the floor of the mountain is simply 10.62m. Technically, we name it overburden. So, if not handled fastidiously, it could collapse anytime. For this, we’re utilizing a pilot tunneling methodology, the place we first excavate a smaller tunnel upfront of the primary tunnel’s development,” he stated.
The tunnel is a part of 8.3-km Bundle-15 of the 1,386-km expressway undertaking. Based on NHAI, the proudly owning authority of the expressway, the price of the tunnel was Rs 1,000 crore earlier than being revised to Rs 1,250 crore.
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Sanjay Kumar, undertaking head and basic supervisor (Engineering Tunnel) of Dilip Buildcon, stated the tunnel is sort of 80 per cent full. “This 8.3 km stretch of the expressway entails the development of the freeway, an open ramp, a coated tunnel and an underground tunnel. The entire size of the underground tunnel is 3.3 km. On the north aspect, there’s a 480m reduce & cowl tunnel. On the south portal, now we have constructed a 1,084m reduce & cowl tunnel. Minimize & cowl is a camouflaged tunnel, which was later made a part of the undertaking as per recommendations from the Forest division because it traverses the protected space. This may assist animals to move from one aspect to a different with out disturbing the habitat,” stated Kumar.
The 4.89-km tunnel in Kota is a key hyperlink of the Delhi-Mumbai Expressway.
“In tunneling, and particularly for such fragile stretches, now we have to resolve our subsequent step at each metre of excavation. On this 500m part, we’re constructing a smaller tunnel, then we are going to widen it to take the form of the primary tunnel. It’s like making a tunnel inside a tunnel. At the moment, on a mean, we’re excavating 1.2m per day. After that, we are going to do benching, the place the decrease half shall be excavated. After its completion, it can join Chechat in Rajasthan to Ratlam in Madhya Pradesh,” stated Kumar, the undertaking head.
Vikas Prasad, a geologist from Jharkhand, explains the challenges. “The rock mass could be very weak and extremely fractured, Due to this, we needed to face some unexpected adjustments within the geological situation. There was very heavy floor water ingress contained in the tunnel. Together with this, as a consequence of heavy rainfall, the tunnel submerged in 2022, 2023 and 2024. Once we began work, we thought we’d get onerous strata however the rock formation is mushy. Additionally, now we have to provide a 100-year assure that the tunnel will stay protected,” stated Prasad.
Surendra Singh, the protection skilled, stated that since excavation is nearing completion, the subsequent step is to put in a sturdy security system. “The tunnel shall be outfitted with the SCADA (supervisory management and knowledge acquisition) system. It can have energy provide, air flow system, hearth combating and hydrant system, hearth alarm, gasoline suppression system, optical linear warmth detection, public tackle, CCTV, emergency phone, gasoline sensor, radio rebroadcasting system, signages, emergency energy, communication & visitors management, lighting and so on,” stated Singh.
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The tunnel passes by means of totally different rock lots and substrata that embody sandstone, shale, siltstone, mudstone and limestone. (Specific photograph by Dheeraj Mishra)
Pardeep Atri, regional officer, NHAI, Jaipur, stated the breakthrough was accomplished on February 20 and April 10. “The tunnel breakthrough is a sensational second, when the tunnel being excavated from each side lastly meets. At this second, for the primary time, the air gushes from one aspect to a different and will increase the oxygen degree,” he stated.
Based on Atri, this tunnel is in an eco-sensitive zone, as a consequence of which there have been considerations from the forest and wildlife division. “We redesigned the undertaking accordingly. Many of the tunnels within the nation are four-lane. We’re constructing two four-lane tunnels right here, which shall be a terrific achievement for the greater than 2,000 individuals who labored on this undertaking. Automobile motion will begin from these tunnels by March 2026,” he stated.