About 300 slopes along the East-West highway alone need to be stabilized

Landslide: In what could possibly be a permanent solution to mitigate the increasing instances of landslides in the country, the works and human settlement ministry with assistance from Japan is experimenting the non-frame slope stabilization method in Dochula, Thimphu.

In this technology, steel bars are driven into the firm layer under ground and base plates installed on its heads to stabilize the soft and less-solid clod. Wire ropes are networked through the bars, which join the base plates and enable in reinforcing the stability of slopes.

The trial implementation of the technology over a slope of 300 square meters was formally inaugurated yesterday.

At the inaugural, works and human settlement minister Dorji Choden said the non-frame method is critical for Bhutan’s road network, where hill road construction is a big challenge given the fragile and unstable terrain.

She said, over the years the Department of Roads (DoR) has tried several technologies to stabilize slopes but the ministry is keen on continuing to learn new technologies to find a better and cost effective solution.

“Finishing this small patch is not the end. We’re hopeful that we’ll be able to replicate this method in other critical areas in the country,” she said.

DoR’s specialist M N Lamichaney said non-frame method is an innovative slope stabilization technique and a disaster prevention technology widely adopted in Japan.

Besides preserving environment, the method also saves resources and reduces waste, can be implemented in any terrain and construction time is reduced by almost 40 percent. It saves at least 10 percent cost in comparison to the conventional slope stabilization methods.

All expenses, amounting to about Nu 5M, for construction and installation of the trial method at Dochula was borne by Nippon Steel and Sumikin Metal Products Co. Ltd.

The company is also the sole producer of construction materials for the technology in Japan. The method was however introduced to Bhutan through institutional cooperation between Kyoto University and Department of Geology and Mines.

A Memorandum of Understanding between the company and the DoR in February this year.

Recently DoR and Kyoto University jointly carried out a research on slope stabilization across the country. An Interim research report will be presented today in Thimphu.

DoR’s engineer Tempa Thinley said a slope management project has identified about 300 slopes along the East-West highway alone that need to be stabilized.

“But we do not have funds to implement the non-frame method on the identified areas,” he said.

DoR will monitor the site at Dochula until October next year to collect data for review on the effectiveness of the method in Bhutan.

Nirmala Pokhrel