[ruzbehxyz]

A test run was carried out by the HPRTC bus through the Atal tunnel on 22nd September.
The bus contained both regional managers of SHO Manali, Kullu, and Lahual & Spiti, Himachal Road transport corporation, Eksain, PWD and BRO representatives. The test run was successful.

Source: SDM, Manali.

[CANPUSH]

I only wonder why they kept it 10.5 m wide. Why they did not made it 14 meters wide to accommodate 4 clear lanes of traffic + median and side walks?

It always beats me when it comes to such constructions. I always feel that when you build a bridge or tunnel, add one more lane on either side as emergency+future expansion. For a 4 lane highway, make bridge/tunnel 6 lane. For two lane road, make bridge/tunnel four lanes.

[arvind71181]

Originally Posted by CANPUSH

I only wonder why they kept it 10.5 m wide. Why they did not made it 14 meters wide to accommodate 4 clear lanes of traffic + median and side walks?

It always beats me when it comes to such constructions. I always feel that when you build a bridge or tunnel, add one more lane on either side as emergency+future expansion. For a 4 lane highway, make bridge/tunnel 6 lane. For two lane road, make bridge/tunnel four lanes.

Usually, I would agree with you, but considering the terrain where this tunnel was built, I think what they have done itself is amazing.

[V.Narayan]

Originally Posted by CANPUSH

I only wonder why they kept it 10.5 m wide. Why they did not made it 14 meters wide to accommodate 4 clear lanes of traffic + median and side walks?

It always beats me when it comes to such constructions. I always feel that when you build a bridge or tunnel, add one more lane on either side as emergency+future expansion. For a 4 lane highway, make bridge/tunnel 6 lane. For two lane road, make bridge/tunnel four lanes.

I am sure the Army planners and BRO had the good sense to think of these points before finalizing their design after studying the rock geology of the mountain. It is likely they are not that stupid. I am surprised to hear these questions from an urban planner. The cost of a 14-metre wide tunnel versus a 10.5 metre wide one is not 35% more - it is about 2.3X more not counting the extra years in time and effort that will be needed and the impact that will have on cost of the project. The width & route of a tunnel is also restricted by the nature of the rock being bored through and more importantly the nature of the adjoining rock and its ability to cope with supporting the hollow of the tunnel without collapsing. It is also limited, in mountainous terrain, by what boring equipment you can get up there through road or helicopter in the first place. And equally importantly what means you have, at that high altitude and mountain terrain, to dispose off the earth & rock that has been bored out.

[distiller]

Originally Posted by arvind71181

Usually, I would agree with you, but considering the terrain where this tunnel was built, I think what they have done itself is amazing.

And adding on to what V. Narayan & arvind71181 said, I think they would have considered the traffic volume for today and coming time. And we need to also consider the distance and hardship saved because of this tunnel.

[ruzbehxyz]

Originally Posted by CANPUSH

I only wonder why they kept it 10.5 m wide. Why they did not made it 14 meters wide to accommodate 4 clear lanes of traffic + median and side walks?

Originally Posted by arvind71181

Usually, I would agree with you, but considering the terrain where this tunnel was built, I think what they have done itself is amazing.

+1
Absolutely correct.

Originally Posted by V.Narayan

I am sure the Army planners and BRO had the good sense to think of these points before finalizing their design after studying the rock geology of the mountain. It is likely they are not that stupid.

+1
Absolutely correct.

Reasons for the current width:-
1. High costs.
2. Inhospitable terrain.
3. In relation to the width, they already have a secondary tunnel for emergency.
4. Volume of traffic is not that much. In fact in last 10 years, the traffic is mainly of tourists in the 6 months when the road is open.
5. The Army has plans in place. If there is a war, or war like situation, such roads are closed and used by Army only.
Eg: With the ongoing problems in Ladakh, the Srinagar-Leh highway was closed for civilians as a safety measure.
So extra width of the tunnel is not justified.

[Sutripta]

Originally Posted by V.Narayan

I am sure the Army planners and BRO had the good sense to think of these points before finalizing their design after studying the rock geology of the mountain. It is likely they are not that stupid. I am surprised to hear these questions from an urban planner. The cost of a 14-metre wide tunnel versus a 10.5 metre wide one is not 35% more - it is about 2.3X more not counting the extra years in time and effort that will be needed and the impact that will have on cost of the project. The width & route of a tunnel is also restricted by the nature of the rock being bored through and more importantly the nature of the adjoining rock and its ability to cope with supporting the hollow of the tunnel without collapsing. It is also limited, in mountainous terrain, by what boring equipment you can get up there through road or helicopter in the first place. And equally importantly what means you have, at that high altitude and mountain terrain, to dispose off the earth & rock that has been bored out.

How does one arrive at the %age cost calculations? Amount of material to be removed (a first approximation very very rough guide for say metalworking) does not lead to 230%.

Agree with all that you say about the difficulty of the job. Add to it that the Himalayas are geologically young and thus unstable. But the fact remains that when it comes to infrastructure, we have a habit of thinking small. Mainly for budget reasons. (Too large a budget, project might not get approved. This has another spinoff in infrastructure projects not being completed on time. Let's not get into that here.) Hope that is not the case in this case.

Sutripta

[ruzbehxyz]

Originally Posted by Sutripta

(Too large a budget, project might not get approved. This has another spinoff in infrastructure projects not being completed on time. Let's not get into that here.) Hope that is not the case in this case.

I don't think so. Simply because the volume of traffic is less and all the reasons mentioned in the above posts.

[mmxylorider]

There is alternative to the tunnel in the current situation. The existing roads might be difficult for heavy vehicles, but LMV will not have that problem. The need to have 365 day motorable road sooner v/s 4 lane road later is a no-brainer. In that region, armed forces mobility takes precedence over civilian luxury.

[ruzbehxyz]

Originally Posted by mmxylorider

The existing roads might be difficult for heavy vehicles, but LMV will not have that problem.

All these roads are tough whether it's a two wheeler, a four wheeler, a truck or a 4x4 Army vehicle. Because it's not about the machine, but also about the driver. That's why they say "Man and Machine".

Any time you go above 8,000 feet, you can be at risk for altitude sickness.

There are three kinds of altitude sickness:-

Acute Mountain Sickness (AMS) is the mildest form and it’s very common. The symptoms can feel like a hangover – dizziness, headache, muscle aches, nausea.

High Altitude Pulmonary Edema (HAPE) is a buildup of fluid in the lungs that can be very dangerous and even life threatening.

High Altitude Cerebral Edema (HACE) is the most severe form of altitude sickness and happens when there’s fluid in the brain. It’s life threatening and you need to seek medical attention right away.

There are loads of articles online for altitute sickness.

By the way, The Atal tunnel is roughly at 10,000 feet.

[ruzbehxyz]

Some additional info about the tunnel.

Rohtang tunnel will bring T-90 tanks, Army infantry combat vehicles closer to LAC.
The all-weather tunnel can take any military traffic, even armoured vehicles.

Talking exclusively to IANS, project Director Colonel Parikshit Mehra said the tunnel has manoeuvred one of the largest shear zones in the history of highway tunneling.
Mehra, who did twin master's degree in tunneling, including the one from Austria, said during excavation the temperature inside the tunnel rose to 55 degrees Celsius before breakthrough and it hardly crossed 20 degrees after that.
On its vulnerability, he said, "The deep tunnels in general are not vulnerable to tectonic effects since they move as a rigid body with shock waves.
"However portal buildings are vulnerable to earthquakes and in our case earthquake loads have been considered in design."

He said for at least two years the BRO would regulate the movement of vehicles through the tunnel. Later, it would be handed over to the local civil authorities.

The tunnel has consumed 12,252 metric tonnes of steel, 1,69,426 metric tonnes of cement and 1,01,336 metric tonnes of concrete, and excavated out 5,05,264 metric tonnes of soil and rocks by adopting the latest Austrian tunnelling method for construction.

Chandigarh-based Snow and Avalanche Study Establishment (SASE) has designed mechanical structures to ensure the safety of motorists by countering avalanches on both ends of the tunnel that remain under snow even during peak summer.
Engineers of SASE, a Defence Research and Development Organisation (DRDO) laboratory, said self-escape snow galleries have been erected for the safety of motorists after studying the local dynamics of avalanches like force and velocity.

Source: https://www.timesnownews.com/india/a...-to-lac/657925

[SmartCat]

Just found out that many countries have built snowsheds on mountain roads:



It involves building a sloping roof over mountain roads, at avalanche/landslide prone areas. Doesn't this seem like a cheaper option to drilling large tunnels in the mountains? The Chinese have built snowsheds at many places on the Karakoram Highway in PoK.

From Wikipedia:

A snow shed or avalanche gallery is a type of rigid snow-supporting structure for avalanche control or to maintain passage in areas where snow removal becomes almost impossible. They can be made of steel, prestressed concrete frames, or timber. These structures can be fully enclosed, like an artificial tunnel, or consist of lattice-like elements. They are typically of robust construction considering the environments they must survive in.

Snow protection is particularly important when routes cross avalanche "chutes", which are natural ravines or other formations that direct or concentrate avalanches.

Snow sheds or avalanche galleries are a common sight on railroads in mountain areas, such as the Donner Pass in the United States or many of the Swiss mountain railways, where tracks are covered with miles of shedding. Although unused today, the Central Pacific Railroad had a complete rail yard under roof in the pass. They are also found on especially hazardous stretches of roadway as well. The Trans-Canada Highway between Revelstoke and Golden in British Columbia has several snow sheds covering both carriageways to cope with the heavy snow.

East of Snoqualmie Pass in Washington in the northwest U.S., westbound Interstate 90 had a snow shed midway along the east shore of Keechelus Lake (47.355°N 121.3658°W, milepost 57.7); it was removed in 2014 in preparation for the construction of bridges to replace it.[4][5] The 500-foot (150 m) concrete structure covered two lanes on a curve and was constructed in 1950 for U.S. Route 10, then one lane in each direction; it marked the first time precast construction was used for a highway structure in a mountainous area and was the last remaining snow shed on an Interstate highway.

[VRJ]

Lovely tweet from Anand Mahindra. BRO ➡️ Bharat Ratna Organisation. Brilliant effort by BRO.



Cheers!

[ruzbehxyz]

Update: 03rd October 2020.

Atal tunnel anuagrated by PM Modi today and is now officially open for all.





Source: https://www.indiatimes.com/trending/...on-522333.html

https://youtu.be/00FQuTO2S1Y

[ruzbehxyz]

Quick facts of the tunnel.



Source: Autocar.