Thursday, September 13, 2012

Planned Nagdhunga-Naubise tunnel not feasible, govt study finds out

KATHMANDU, SEP 13 - 2012

A study conducted by the government has found that a proposed tunnel linking Nagdhunga and Naubise on Tribhuvan Highway is not feasible due to steep terrain and longer distance. The survey has recommended building five shorter tunnels elsewhere instead—Sisne Khola-Sikre Khola and two each linking Imakhel, Thankot-Sisne Khola and Sikre Khola-Khani Khola—as the slopes on these routes are within acceptable levels.

“The proposed 7.7 km road will have a gradient of 5.71 percent although the preferred slope is a 4 percent tunnel road,” said Prabhat Jha, senior divisional engineer at the Department of Roads, the implementing agency. “The slope could be acceptable if the distance was shorter.”

The recommended shorter routes will be 1.7 km to 2.32 km long and the slope will be from 4 percent to 5.88 percent. The government is discussing deciding on the

Imakhel-Sisne Khola route. Among the other suggested alignments, three are shorter but steeper.

The government has proposed building a tunnel through the hills in the west of the valley to shorten travel time and smoothen motor traffic between the capital and the main route to the outside world.

According to the preliminary study for a detailed feasibility study conducted by consultant GEOCE in a joint venture with Tech Studio of Engineering, the length and slope of the proposed route is not suitable for a tunnel. The Naubise-Nagdhunga tunnel will have to deal with ventilation and security issues too. The consultant has sought the government’s decision regarding the tunnel alignments so that it can concentrate on particular alignments while conducting a detailed feasibility study.

The same consultant has been conducting a feasibility study for a proposed Tokha-Gurje tunnel in the northwest of the valley. A preliminary report shows that the proposed route has a 3 percent slope. The department said that this tunnel would be 4.45 km long and link Geragaun (Gurje) with Ganesh Khola (Tokha).

The government plans to complete studies for the two proposed tunnels this year and prepare a detailed project report. The consultant is expected to complete the feasibility studies and recommend possible alignments by next month.

Source: The Kathmandu Post

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