Earthquake-resistant materials can reduce damage
The massive earthquake that hit Nepal on April 25, 2015, caused immense destruction to man-made structures leaving nearly four thousand people dead. It is impossible to accurately predict the occurrence of earthquakes, but this does not prove that resilience or casualties from earthquakes are beyond man’s control. These are largely within our control.
Even when earthquakes of higher magnitude occur in prosperous countries where buildings are earthquake resistant, the casualties are far, far less. For instance, a report in the Economic Times points out that it is the usage of earthquake resistant steel like TMT bars in large construction projects which did not lead to as many casualties as reported from the tremor-torn Nepal.
The Ministry of Environment and Forests (MoEF) has recommended the use bamboo houses that are earthquake resistant. In 2012, the Indian Plywood Industries Research and Training Institute (IPIRTI) , an autonomous body of the MoEF, developed a bamboo-based house which resisted typical Zone 5 earthquake that would fall under very high damage risk zone, without any significant damage even after seven repetitions.
In India, most buildings are not earthquake resistant. According to an estimate, nearly 70% of the buildings in East Delhi are not safe. In fact, the building standards are so pathetic that India’s first earthquake resistant building, the government school at Ludlow Castle in north Delhi, which was retrofitted, was completed in 2008. To make the building earthquake resistant, the beams of the building were wrapped with earthquake resistant materials.
The National Disaster Management Authority has stipulated that all new constructions in Delhi and Mumbai should have earthquake-resistant structures.
How to ensure that your houses are earthquake resistant
1. Check construction aspects like design, materials used and foundation. Upgrade your home if necessary. Buy earthquake insurance if available.
2) Elizabeth Hausler, an earthquake engineer who runs an NGO, Build Change, points out that by soaking bricks in water before building a wall, the strength of the wall can be doubled.
3) According to Hausler, houses built with wood/bamboo or lightweight steel can withstand an earthquake more than structures made of bricks and stones. Traditionally built timber houses are safer than heavier concrete buildings
4) By using lightweight material, especially on the roof, you can make the structure and the foundation resistant to sideway loads. Make the roof as light as possible. Avoid compression structures like domes, vaults and arches.
5) You can reduce the vulnerability of large buildings by using bearings or dampeners.
6) After the 8.0 magnitude Mino-Owari earthquake of 1891 destroyed over 140,000 homes, Japan abandoned brick and masonry construction.
7) Homebuyers should make sure that builders give them a structure certificate saying that the building has earthquake resistant elements.
What you should do when an earthquake occurs