GUWAHATI, Jan 8 - People of the State, who are living in engineered buildings, including the high-rise ones, need not panic in the event of any earthquake having the released energy (magnitude) of 8 and above and the shaking (intensity) of 9MMI, said president of the Assam Real Estate and Infrastructure Developers� Association (AREIDA) PK Sarma.
Sarma, who was talking to this newspaper here on Thursday, said that the engineered buildings of the State are earthquake resistant. They can withstand earthquakes up to the above magnitude and intensity. These structures are built as per the Earthquake Code - IS 1893, he said.
The bridges and flyovers of the State are also built as per the provisions of the separate IS Codes meant for their construction, Sarma said.
However, he maintained that the same cannot be said about the unauthorised structures, which have been built without following the Earthquake Code. In Guwahati alone, there are around 70,000 unauthorized buildings constructed on the encroached Government land, Reserve Forest areas, wetlands and 16 eco-sensitive hills of the city. These buildings definitely pose a serious hazard, he said.
The Earthquake Code � IS 1893 � was notified in the country in 1962. Considering its history of devastating earthquakes, this Code was made mandatory in Assam, whereas it remained an advisory in other parts of the country. It was revised in 1984 and following the 2001 Bhuj Earthquake, it was again revised in 2002.
This Code was followed even in Nepal and those buildings, which were built as per this Code could withstand the April 26, 2015 devastating Nepal earthquake. The buildings, which were built in both the valleys of the State as per this Code have responded well to the jolts of around 19 earthquakes of various magnitude and intensities, including some major ones like the August 20, 1988, Indo-Nepal border earthquake of 6.8 magnitude, the September 18, 2011 Sikkim earthquake of 6.9 magnitude, the April 26, 2015 Nepal earthquake of 7.8 magnitude and the January 4, 2016 Manipur earthquake of 6.7 magnitude, Sarma said.
In the construction process of the engineered buildings, there is a very strict enforcement system in place. Registered technical persons like the geo-technical engineers, structural engineers, architects, supervisors are to be engaged mandatorily for construction of such structures, he said.
Therefore, people living in the engineered structures should stay indoors, abiding by the safety norms like sitting next to a structural member like a beam and column, in the event of any earthquake. The cracks in the walls and other non-structural members are permissible under the Earthquake Code and this should not cause panic as long as the structural frames are safe, intact, said Sarma.
On the structural safety of the bridges and flyovers of the State, he said that these structures are so built that they can withstand major earthquakes. The fact that the massive blast of a bomb beneath it could not do any major harm to the Ganeshguri Flyover in Guwahati on October 30, 2008 substantiates this assertion, said Sarma.
Guwahati buildings: After the Bhuj earthquake in 2001, buildings in Guwahati were subjected to numerous studies by various agencies, both national and international. All of them have reported favorably. The most recent technical study was conducted by a Norway-based international scientific agency called NORSAR, in association with the Assam Engineering College and funded by the Royal Embassy of Norway.
This project examined around 16,000 buildings in Guwahati. Experts from Norway and Assam Engineering College imposed simulated earthquakes like the Nepal earthquake or even bigger including the Great Assam Earthquakes of 1897 and 1950, to assess their impact on these buildings. They have stated in their final report that the resilience of Guwahati buildings to probable earthquake is far better than buildings studied in other Indian cities, said the AREIDA president.