Safety lies in being traditional
"EARTHQUAKES don't kill, buildings do," says John Beynon, principal architect at UNESCO's regional office in Bangkok. Today, people are shifting to "killer buildings" as they give up their traditional building technologies in favour of modern designs and materials. This disastrous transformation has taken place not just in Garhwal, but idso in areas like Iran, Pakistan, and Turkey. According to Beynon, traditional Asian architecture "is a perfect response, with its lightweight, interconnected, yet flexible, wooden structures."
Four of the 20 earthquakes with the highest casualties of this century have been in Iran, but the earthquake that hit Manjil in June 1990 far exceeded previous disasters both in the death toll and the scale of destruction.
A team from the UN Office of Disaster Relief (UNDRO), which visited the scene of the devastation, reported that the traditional, timber-framed buildings with a wattled and daub infill on a masonry plinth resisted the shock much better than the other structures.
Because of shortages of timber,people have now begun to make use of steel framing members and fired brick masonry with cement mortar. The worst-affected structures were the two-storey brick masonry ones with steel frames. Yasemin Fatma Aysan, an architect and disaster expert at Oxford Polytechnic, UK, feels that scarcity and the high cost of traditional building materials and the loss of fine building skills are the problems being faced in many rural areas.
Although traditional buildings fare better, environmental degradation and a rising population are forcing people to look for alternative materials. Now materials require new stills which are often acquired without a good understanding of the principles of safety.
The UNDRO recognised that it would be difficult for Iran to find sufficient timber to reconstruct the devastated towns with safe buildings, but it still recommended that, wherever available, timber should be used.
Traditional knowledge is itself a learning process. According Aysan, historical records show that the transition from masonry to wood frame construction in Istanbul took place after the 1509 earthquake, which destroyed over a thousand houses and log mosques.
Yet what is learnt from the past is soon forgotten as scarcity of suitable raw materials lead to the adoption of inappropriate technology. In India, after the great Kangra earthquake of 1905, all the houses in the region were razed to the ground and no one was left alive even to carry out rescue operations, The new district head-quarters was rebuilt in Dharamsala with wood-framed, brick-nogged buildings. But, in course of time, wood became scarce, and these buildings were replaced by brick-and-stone constructions.
"It was clear that they were not suited to withstanding earthquakes," says A S Arya, a scientist emeritus of the Council for Scientific and Industrial Research (CSIR). Arya cautions that if nothing is done immediately, a future earthquake which measures 8 an the Richter scale can lead to the complete collapse of 1,45,000 houses and partial collapse of 2,68,000 houses within an area of 7,90,000 ha. At present only 2.4 per cent of the total housing stock in Himachal Pradesh have wood and concrete walls which can resist moderate earth-quakes.