IIIT to check earthquake effect on Hyderabad buildings

Hyderabad: The International Institute of Information Technology (IIIT) Hyderabad has developed graphs to assess damage to buildings in the event of an earthquake.

It has installed hi-precision state-of-the-art building vibration sensors in Chandigarh, which it claimed, provides real time check of the correctness of the graphs.

The technology called 'Tool for Comprehensive Seismic Risk Assessment of Buildings (CSRAB)' has been developed by Professor Ramancharla Pradeep Kumar, head of the Earthquake Engineering Research Centre at IIIT and his research team.

According to Kumar, this new damage assessment method can clearly say by looking at a prototype score card what kind of damage a building can undergo in future earthquakes.

The score card is called the Rapid Visual score of the building.

In this, the damage can be categorised under five categories - no damage, slight damage, moderate damage, severe damage, and collapse.

He said risk assessment has three components - hazard, exposure, and vulnerability. Hazard is the level of ground shaking expected at any location, exposure is number of people exposed to such a hazard and vulnerability is current strength of buildings.

"Hazard may not be under anyone's control, exposure is in hands of government policies and vulnerability is in individual/engineer's hands," he remarked.

More than 60 per cent of the land area in India is earthquake prone with 12 per cent of area coming under zone 5 which is severe most zone, 18 per cent coming under zone 4, 26 per cent under zone 3 and 44 per cent area under zone 2-the least zone (least zone does not mean that no earthquake will occur), Kumar said.

It is imperative for India to develop strategies to predict risk assessment of buildings as 82 per cent of the population is living in 52 per cent of the land areas.

Kumar stressed that fifty years ago earthquakes in India or say Tokyo or California would have caused similar damage.

However, today the damage in India would be way above California or Tokyo for a similar level of ground shaking or the similar magnitude on Richter scale because of poor construction quality in India, he said.

For the first time, a project was taken up in 2009 in Gandhidham and Adipur cities in Gujarat, which come under zone 5 and 4, a mammoth exercise of surveying 15,000 buildings.

Another project was taken up in Nanded-Waghala city and one more in Himachal Pradesh.

Kumar used "expended energy based damage assessment model" developed by him to link the rapid visual survey score of a building to the seismic risk assessment of the same.

"This will help both individual home owners to know the vulnerability and risk status of their building and the government to know the status of built environment in their region," he said.

To check the correctness of the damage graphs, IIIT Hyderabad has taken up another project called Disanet under an Indo-Japan collaboration research.

Japan has supplied sensors and the project will be implemented in Chandigarh, which is very well planned city with good construction quality and is in the Indo-Gangetic area, which is a highly seismic prone, he said.

The total project cost is Rs 20 crore and institutes including NGRI, IIT Hyderabad, IIT Kanpur, IIIT Hyderabad and University of Tokyo, Japan are involved.

Under this, they are jointly assessing the building vulnerability using vibration sensors installed in different buildings of various construction varieties.

"Chandigarh is a real time experiment in which sensors validate the graphs or vulnerability assessment," Kumar said.

He said they are working to improve the map further and develop technologies to ensure that life loss is less in earthquakes and damages to buildings also comes down. This is possible if safe construction practices are followed.

The day will not be far off when earthquake prediction will be just like prediction of cyclones, he said.

These sensors have so far recorded data of over 20 micro and minor earthquakes from Chandigarh.

"Even though the vibrations amplitude may be weak, it is possible to study building response and make prediction on type of response for possible moderate to major earthquake events," Kumar said.