Earthquake resistant structures

The Himalayan belt is considered as one of the most seismically active intra-continental regions of the globe. In the past, this region has witnessed several moderate to great magnitude earthquakes and a few very great (M>8.0) earthquakes along its about 2400 km long belt.

As per the officials, the seismicity in this region is mainly attributed to the Main Himalayan Thrust along which Indian plate under thrusts beneath the Himalayan wedge.

According to the seismic zoning map of India prepared by Bureau of Indian Standards (BIS), the country has been divided into four zones viz. zone V, IV, III and II

A total of 59% of the land mass of India, covering all states, is prone to earthquakes of different shaking intensities.

Zone V is seismically the most active region, while zone II is the least. Approximately, 11% area of the country falls in zone V, 18% in zone IV,  30% in zone III and remaining in zone II.

Zone V includes Parts of Jammu and Kashmir (Kashmir valley and Doda district), western part of Himachal Pradesh, Eastern part of Uttarakhand, Rann of Kutch in Gujarat, part of Northern Bihar, all northeastern states of India and Andaman & Nicobar Islands.

Zone IV includes remaining parts of Jammu & Kashmir, Ladakh, remaining part of Himachal Pradesh and Uttarakhand, some parts of Haryana, Parts of Punjab, Delhi, Sikkim, northern part of Uttar Pradesh, small portions of Bihar and West Bengal, parts of Gujarat and small portions of Maharashtra near the west coast and small part of western Rajasthan.

The central government in the winter session of the Parliament, concluded not long back ago, informed that scientists have indicated that strain accumulation for the earthquake occurrence is currently going on along the Main Himalayan Thrust, “where great earthquakes are expected to occur”.

In view of the statement, there is need for regular awareness campaigns to sensitize people on prevention and preparedness for building safety from earthquakes.

There is a need to accept earthquakes as a reality and do everything to redefine development plans, especially in terms of building quake-resistant buildings.

Concerned authorities are poised to follow guidelines by the Bureau of Indian Standards, Building Materials and Technology Promotion Council (BMTPC) and Housing and Urban Development Corporation (HUDCO) etc. for design and construction of earthquake risk resistant structures to minimize the loss of life and damage to property caused by earthquakes. While these guidelines are in wide circulation amongst the administrative authorities responsible for the design and construction of earthquake resistant structures in earthquake prone areas, there is need to ensure adherence and the government should take periodic reviews.

Related Articles