Odisha Sun Times Bureau
Bhubaneswar, May 23:
A mild earthquake that struck Odisha on Wednesday night has raised questions on the durability and endurance of the high rise buildings in the state and the safety of the people who live in such tall structures.
Reports said that several high rise buildings in the state have not adopted the quake-resistant technology.
It may be mentioned here that the state government had assigned a team of geo scientists comprising Prof KL Pandya, PN Nayak, Dr Rabindra Nath Hota and Dr KC Mohapatra of Utkal University way back in 2000 to study the state of the earth layers in the coastal region.
The team, in its report, had stated that since there are some hidden faults in the sub-surface layers at some places including Bhubaneswar, there is every possibility of the movement of the plates under the layers.
The team had also observed that Odisha comes under the fault line that stretches from Kashmir up to the Himalayan foothills.
“Though Odisha comes under zone number-3 or a moderate risk zone, the possibility of earthquakes in the state cannot be ruled out”, the report said.
According to Dr Hota, the extent of damage to the buildings depends on the pattern of their construction while taking the intensity and the duration of the earthquake into consideration.
“Keeping this in view, the basic structure of the buildings should be in the shape of a cage to sustain the tremor”, he observed.
“It is not a fact that there are possibilities of quakes at all the places. However, the devastating quake in Latur in Maharashtra on September 30, 1993, has forced the geo scientists of the world to come to a conclusion that there should be preventive measures in place in the areas that are least prone to earthquakes.
Talking about the safety measures, well-known geo scientist Amalin Patnaik said, quakes of magnitude 6 in the Richter Scale could result in jolts that can lead to cracks in the walls and cause damage to weak structures.
It is the first jolt which is the most powerful and cause damage to the structures, he said, adding, the aftershocks that gain energy from the tremor cause devastation by destabilising the already weakened structures.
Aftershocks are dangerous because they are usually unpredictable. They can be of a large magnitude, and can collapse buildings that are damaged from the main shock. Bigger earthquakes have more and larger aftershocks and the sequences can last for years or even longer especially when a large event occurs in a seismically quiet area, Patnaik pointed out.
Considering the above, emphasis should be given on the designing of the plinth band and lintel band for the high rise buildings to sustain and survive high magnitude tremors.
“If such techniques have not been applied to the high rises that have come up at several towns and cities of the state, the possibility of massive loss of life can not be ruled out”, he warned.