Monday, 27 July 2009

Bhutan : First retrofit in Thimphu

27 July, 2009 - It is not much of a building to look at. The floor and the walls facing the street have been torn down as if the entire structure is to be demolished.

But it is a work in progress towards, what engineers of the standard and quality control authority (SQCA) call, a prototype retrofit building that will be less vulnerable to earthquakes.

Retrofitting in buildings is normally done to strengthen the building, by adding new material and equipment.

The three-storied building near the SNS restaurant, above the archery ground in Changlimithang, is the first one in Bhutan to go for retrofitting, with support from SQCA. The modifications on this building, built 20 years ago, started from this April. It’s expected to be completed by next year.

The building-owner’s nephew, Thinley Palden, told Kuensel that a total retrofit is being done on the building. “We’re working on the foundation, strengthening the pillars and adding two more floors. It’s like building a new one altogether. Given the situation and the location, it’s better to retrofit rather than to demolish and rebuild.”

With this building, the SQCA is hoping to create awareness among other building-owners to promote retrofitting, as Bhutan is in seismic zone V, as per the Indian seismic zonal map, which is severe, said SQCA officials. Buildings built before 1997 do not have the seismic design concept incorporated in building construction.

A seismic designed building is built to resist the tremors of an earthquake. The seismic design concept requires all building drawings in urban areas to incorporate features, such as deeper foundations, more dense bindings around metal rods inside pillars, stronger beams and columns and the right mix of cement, sand and gravel.

Buildings in Bhutan mostly fall under two categories - reinforced cement concrete (RCC) and load bearing buildings. It is now mandatory for all new constructions in urban areas to incorporate ‘seismic design’ features.

Whether retrofitting is cost effective is not known, as of now. “It’s a bit early to comment on the cost. But studies done in India and Nepal show that it’s just 15 to 20 percent of the total cost of the building,” said the chief executive engineer of SQCA, Rinzin Namgyel, adding that it could be costlier in Bhutan as the material and labour are imported from India.

SQCA started in 2005 an earthquake risk management project, funded by UNDP. Phase I of the project began with preparatory assistance for studies to be carried out. Phase II focused on assessment of 15 buildings in Thimphu in 2007, of which two buildings had to be selected for retrofitting. The two buildings were from the NPPF colony. However, it did not happen, as the management wanted to demolish and build new ones instead.

Under the present phase III, funded by UNDP, with support from the government of Japan, SQCA carried out a rapid visual assessment of buildings in Samdrupjongkhar and Phuentsholing. The report is still in preparation.

Since the initiation of the project, SQCA made numerous announcements to provide free technical assistance in retrofitting, but response from house owners was poor, said officials.

The chief executive engineer said, “The present model building will be the only building and, in future, we won’t be able to do it because of the project deadline.”

Meanwhile, construction of a two-storied model earthquake resistance building will soon begin in the SQCA premises. The building, according to the chief executive engineer, will demonstrate earthquake resistance features to be incorporated in rural types of building.

By Kinga Dema

Tag : bhutan,thimphu,paro bhutan,druk air

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