Frequent tremors highlight the need for ‘tall building council’

The frequent tremors in Guntur and Vijayawada highlights the need for a ‘tall building council’ that will check whether norms related to earthquake resistance are followed by planners and builders in going for vertical expansion.

“Loss to life and property will be more in earthquake-prone areas as most buildings in these localities are highly vulnerable to quakes. Thus, setting up of council is essential to ensure that new buildings are safe for residents,” said Ramancharla Pradeep Kumar, professor and Head of Earthquake Engineering Research Centre of the International Institute of Information Technology, Hyderabad.

The council assumes importance in the wake of State government planning construction of high-rise buildings in the capital region – Amaravati.

On Monday afternoon, mild tremors were felt near Narsaraopet in Guntur district causing panic among villagers. Guntur witnessed tremors in February last while Vijayawada and its surrounding areas felt the impact of the 7.9 magnitude temblor that shook Nepal three months ago.

A seismic study conducted by the centre confirms that ‘as per seismic hazard map of Bureau of Indian Standards’, 34 per cent of the area in the undivided AP is susceptible to quakes of intensity VII' which is similar to the scale of the Bhuj earthquake of 2001 (6.9).

Seismic history of the undivided AP shows that the State has experienced earthquakes of magnitude up to 5.7 on the Richter scale i.e., Vizianagaram (magnitude 5.5) in 1917, Ongole (5.4) 1967 and Bhadrachalam (5.7) in 1969.

Mr. Kumar said Mumbai, Latur, Chennai, Jabalpur, Bangalore, Tirupati, Vijayawada, Warangal, Bhadrachalam, Ongole and Kolkata fall under zone III.

“There is possibility of earthquakes measuring up to 7 on Richter scale in zone III in the next 200 years,” Mr. Kumar explained, while insisting that the danger cannot be overlooked.

Three areas in Vijayawada with ‘silty-clay soil’ are likely to incur ‘severe damage due to earthquakes of higher magnitude’ because the soil amplifies the seismic waves. This was confirmed by three research scholars from the IIIT Hyderabad Centre who conducted a detailed study in 2011 on the impact of earthquakes on 14 localities in the city based on ‘geological and geotechnical factors.