“Make the Atal Tunnel venture a scenario study for the entire world” — words by none other than our quite possess Primary Minister, Narendra Modi, go out of their way to inform us how critical and successful this venture has been.
But then the questions arise — what is the Rohtang Tunnel venture? Why did we want it in the very first location? How is it advantageous to us at all? Well, don’t worry, in contrast to the well-liked perception, the solutions will come strolling to you for this one particular!
The What and the Why?
The Rohtang Tunnel, or the Atal Tunnel, is a highway tunnel created under the Rohtang Go in the jap Pir Panjal selection. Named after our previous Key Minister Atal Bihari Vajpayee who initiated the development process, this tunnel is the longest tunnel ever manufactured earlier mentioned the elevation of about 3100m, which makes this task even a lot more marvellous!
The tunnel reduces the travel time and general distance among Manali and Keylong, on the way to Leh. The route, which previously went via Gramphu, was 116 km long and took 5 to 6 hrs in very good circumstances. The traveller now reaches the South Portal of the tunnel from Manali, a length of 24.4 km in about 50 minutes, goes through the 9.02 km extended tunnel in about fifteen minutes and reaches Keylong which is forty five km away in about sixty minutes.
The new route by way of the tunnel provides down the whole length travelled to 78.42 km which can be protected in about 2 several hours and five minutes, a reduction of all around three to 4 hours when in comparison to the previously route. And if that is not great enough, the tunnel bypasses most of the web sites that were susceptible to road blockades, avalanches and traffic snarls. Hence escalating the security of the travellers and additional reducing their travel time. The last price of the entire project is close to ₹3,two hundred crores, after the whole project becoming revised three occasions.
A marvel of Civil Engineering — an extraordinary feat!
The journey for all wonderful achievements is met with hardships — issues that were faced, solved and conquer. Rohtang la tunnel was no various, having difficulties, even more, more durable than the common.
The large altitude, topography, lower temperatures, drinking water ingress — you title it. The development of the Atal Tunnel was no simple process. But like constantly, the Border Street Business (BRO!) solved these problems environment however yet another example of engineering.
Some of the numerous roadblocks confronted had been –
Drinking water Ingression — Seri Nullah (or Seri Nalah), a glacier-fed rivulet flowing via tunnel cavities caused all the menacing drinking water ingress on the south portal of the tunnel.
Very Reduced Temperatures — This kind of minimal temperatures had imposed the require for unique, bolstered concrete. The situation in the course of the winters was even worse, exactly where even the access route to the south portal essential continuous snow clearance.
Topographical Format — The peculiar topography of the mountain range by way of which the tunnel is being excavated precludes any functional likelihood of a shaft or adit. This meant the excavation could be tried only from the two portals, of which the North Portal is not accessible for much more than fifty percent the 12 months.
Learnings in development
The Rohtang Tunnel is experiencing extreme problems owing to the way the task has been conceived. The tunnel structure with a uni-directional twin-tube would have almost certainly essential a simpler support system and one particular of the tubes could have been utilized to open up far more excavation faces for the other tube, specifically in the stretches like Seri Nala. The rock lessons in the Rohtang Tunnel are based mostly on the NGI ‘Q’ system, which is an empirical system and does not take into thing to consider proper geomechanical modelling of the rock. The perseverance of the ‘Q’ price alone is conjectural and may range from geologist to geologist. This can make the method of rock class perseverance tough and contentious on site. A much more sturdy program based mostly on floor behaviour requirements to be adopted.