Bamboo Houses Stand Up To Earthquakes
It is called the "poor people's timber" and even in China it is not accepted as a modern building material. But bamboo, like lumber, makes a light, flexible house that is much better than "modern" materials at surviving earthquakes. Now International Network for Bamboo and Rattan (INBAR) is actively promoting it as a replacement.
"So far, massive construction or reconstruction means concrete structures in China, and bamboo is little known for this [building on a large scale]," says Shayam Paudel, INBAR's director of bamboo housing programs, in the Christian Science Monitor. Unlike the "Tofu" concrete structures that collapsed and killed thousands of kids in substandard buildings, bamboo makes a much simpler structure.
INBAR notes that:
-At least 600 million urban dwellers in Africa, Asia and Latin America live in "life and health-threatening homes". At least one billion people do not have access to safe and healthy shelter and the number will increase dramatically with population growth if the appropriate action is not taken (UNEP, nd).
-One billion people live in bamboo houses. In Bangladesh, 73% of the population live in bamboo houses. Bamboo provides pillars, walls, window frames, rafters, room separators, ceilings and roofs.
-It has been calculated in Costa Rica that only 70 ha of bamboo plantation are sufficient to build 1000 bamboo houses per year. If these houses were built with timber, 600 ha of natural forest would be destroyed each year.
-Studies show that processing of bamboo requires only 1/8th the energy for processing of concrete and 1/3rd of that of wood to create a building material of the same capacity. In comparison to steel, bamboo needs only 1/50 of the energy for processing (Roach 1996).
- Due to the lightweight and favorable elastic properties of bamboo, buildings made from it are very good at resisting earthquakes. All 30 houses in the epicenter of a 7.6 magnitude earthquake survived without any damage in Costa Rica.
- Bamboo possesses excellent strength properties, especially tensile strength. Study shows that bamboo is as strong as wood and some species even exceed the strength of Shorea robusta and Tectona grandis (Sattar, 1995).
According to the Christian Science Monitor:
While much of modern-day building in China is done with steel and concrete, ancient Chinese intellectuals preferred living in retreats made of bamboo, a plant whose qualities were often likened to the character of an honorable man.
In Yunnan Province, which borders Sichuan, the Dai minority still lives in bamboo homes. And in affluent Zhejiang Province, where bamboo is plentiful, local officials have been encouraging architects to design recreational infrastructure using bamboo.
Building experts in China who have been testing bamboo give it the seal of approval for building in the seismic zone.
"Bamboo can be an excellent engineering material. The technology is mature. We believe the bamboo and plywood with a steel frame should be good for earthquakes," says Chen Xu He, formerly a Chinese Academy of Forestry researcher, who tested the bamboo panels used in the INBAR models. via :Archinect