Decongesting Thimphu

Tunnel Proposal: Technical and possible financial help from Norway

Department of geology and mines (DGM) identified tunnel sites
Travel time within the country could be reduced from days to hours and even minutes if a government plan to build tunnels through mountains connecting major valleys is implemented.
The department of geology and mines (DGM) has already identified three potential sites for tunnels. The first and most probable is a tunnel from Thimphu to either Punakha or Wangduephodrang.
The second is a 12 km tunnel between Bumthang and Mongar bypassing the Thrimshingla pass, which is expected to cut 30 km of travelling distance on the East-West highway. The third is from Khasadrapchu in Thimphu to Shaba in Paro, with a tunnel length of nine kilometers, reducing travel time from 45 to 20 minutes.


Pre-feasibility studies have already been done by DGM, indicating that they can be done. “The Wangdue/Punakha tunnels can decongest Thimphu and allow people to settle in these two valleys and also reduce the travel distance and time by around 40 km,” said DGM chief geologist, Ugyen Wangda.

DGM is considering the Norwegian geotechnical institute (NGI), regarded as one of the international pioneers in tunneling as its partner. NGI already has some ongoing projects with Bhutan that have to do with landslides and stabilisation of surfaces.

A NGI team is expected to visit Bhutan again on March 16 to carry out feasibility studies on the tunnels, especially on the Thimphu-Punakha/Wangdue route.

“NGI has the technical expertise to guide the construction of tunnels and is also looking for funding for these tunnels from the Norwegian government, which could be given as grant,” said Ugyen Wangda. He said that funding would make the difference from changing these concepts into reality.

According a department of roads engineer, the Norwegian government in 2005 had already assured NGI of fund to construct a one-kilometre tunnel to bypass the Jumja slide site, but the government did not take up the offer.

The DOR engineer said, “Dantak came forward and said they would take up the project, so the project money and technical assistance from Norway went back.”

Dantak officials, however, told Kuensel that there is currently no plan to build any tunnel at Jumja and that the project had been shelved.

A major challenge, according to DGM, will be the cost, as each km of tunnel would cost above Nu 200 mn.

Ugyen Wangda said that a priority for government is also in reducing the distance between north and south Bhutan like Thimphu-Phuentsholing.

A concept is a tunnel from Damchu near Chuzom till Ganalakha, which could reduce the 170 km distance between Thimphu and Phuntsholing to just 80 km, which in time is down from six to two hours.

“Though the costs will be huge, it’s economically worth it as marble deposits are running out in the south for cement industry but mountains of it are available in the north,” said Ugyen Wangda. The Transport Master plan till 2027 also identifies 12 tunnels to reduce distances.

Ugyen Wangda said that tunnels would be easier to build in the north and west of the country due to the hard and more stable rock face.

Explaining the technology behind tunnels, Ugyen Wangda, who did his thesis on Norwegian tunnels, said that, after the surveys, tunnel-boring machines would first bore the mountain. It would then be lined with heavy steel frames, concrete support and also rock bolting in required places.

“Unlike a hydropower tunnel, people will be travelling through the tunnels, so it’ll have to have very high safety standards” he said.

By: Tenzing Lamsang
Source: Kuenselonline

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