New Delhi: Waste tyres can be a great environmental concern but a professor at a Japanese university hailing from Assam has developed earthquake resistant techniques using them which he says can be effective and affordable means to minimise impact on buildings.
These techniques can be implemented all over the world, especially in Asia, says Hemanta Hazarika, professor in the Department of Civil Engineering at Kyushu University in Fukuoka.
Hazarika, who is the secretary of a technical committee of International Society of Soil Mechanics and Geotechnical Engineering (ISSMGE) related to Geotechnical Natural Hazards in Asian region, is currently in Nepal as part of a Japanese expert team dispatched to the quake-ravaged country.
He has patented one of the techniques and a prototype construction of tyre-retaining wall is planned in Japan within the next few months to replace a conventional retaining wall, which was completely damaged by last year's earthquake in Nagano.
"These techniques can preserve the environment, mitigate disaster and reduce cost. Judicious combination of these three factors is very important for innovative construction techniques," 47-year-old Hazarika told.
As dumped tyres will be used in the construction, these techniques are very affordable in developing countries as they are cost effective as compared to other existing techniques which can only be afforded by rich nations, he says.
Elaborating on the techniques, Hazarika, an alumnus of IIT-Madras, says the first one is related to retaining wall protection from earthquake.
Tyre chips are used as cushion to prevent damage of waterfront structure during earthquake.
"The second technique is related to protection of private houses against earthquake shaking and related phenomenon such as liquefaction. Here also tyre chips or tyre chips mixed with sand or gravel are used.
"The third technique is about protection of sea wall and river embankment from scouring and erosion due to tsunami and wave effect. In this technique, whole tyres are used.
"Since tyres do not look good, planting of trees and shrubs are suggested and our field experiment shows that tyre can be planted easily and plants can cover them to make the surrounding green," he explains.
Test results have indicated that the use of these techniques leads not only to reduction of the seismic load, but also the seismically induced permanent displacement of the structure.
The techniques also could prevent the bumpiness of the backfill after an earthquake, thus maintaining the performance of infrastructural facilities after strong earthquakes.
Besides killing thousands of people, the killer earthquake has also had a heavy toll on buildings.
According to estimates, at least 175 residential buildings were destroyed in central Kathmandu while nearly 150,000 dwellings collapsed across the country.
Hazarika had been in Nepal twice as part of the ISSMGE to study natural hazards issues, especially earthquakes, liquefaction and landslide.
He says he would be more than happy to share his expertise and explore possibilities of implementation of his techniques in India.
"Northeast of India which has high probability of similar earthquakes as in Nepal needs utmost disaster mitigation measures. It is time to act now otherwise it will be too late," he warns.
