As per Wikipedia, An Earthquake is caused due to the sudden release of energy from Earth’s lithosphere that creates seismic waves which result in the shaking of the surface. Due to the level of uncertainties, Building Earthquake resistance structures are the ultimate challenge for structural engineers. An Earthquake resistant structure should be capable to withstand sudden ground shaking to minimize structural damages, human death and injuries.
In general, Reinforced Concrete has enough Earthquake proof of buildings but the cause of failures during earthquakes are usually due to the poor mix design of concrete and it is not properly cured to achieve its designed compressive strength.
How do you protect buildings in a country bedevilled by earthquakes?
We all know that Japan is in a Severe Earthquake prone area where frequent Earthquakes are common. Researchers and citizens are constantly finding the solution for building Earthquake proof buildings.
Instead of using steel or concrete, a Japanese textile firm turned to carbon-fibre ropes. The company, Komatsu Seiren, had developed a high-tensile twine from carbon-fibre composite.
Seeking to reinforce the structure of its new showroom and laboratory in Nomi, it asked Japanese architects Kengo Kuma and Associates to use rods of the material to anchor it. “Since the carbon fibre is tough and pliant, they approached us with an idea of utilising it to render the building quake-resistant,” says Shun Horiki, the project’s lead architect.
The team attached 1,031 rods to the roof and tethered them to the ground. “The principle is quite straightforward,” says Horiki. “When the building jolts left, the rod on the right pulls it back, and vice versa. A curtain of 2,778 rods inside adds a further layer of stability.
This diagram shows tensile strength applied to the exterior rods during an earthquake. Red shows the areas of most tension, ranging through to yellow and then blue, where there is least
“The carbon mesh inside and the drape outside help restrain the horizontal force of the earthquake,” he says.
Before attaching the rods, Kengo Kuma and Associates enhanced the strength of the building’s parapet in order to resist tensile stress and placed anchors around the structure to prevent the ground from rising up.
This is the first time that carbon fibre has been used in this way, but Horiki believes the rods could also be applied to flexible structures such as wooden buildings that “tend to sway horizontally”.
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