GUWAHATI, Oct 14 – Former Commissioner and Secretary of the State Public Works Department (PWD) Karuna Dutta Lahkar has pleaded for assessment of the structural safety of the city buildings granted permission, specially by the Guwahati Municipal Corporation (GMC), between 1985 and 2005. Lahkar, also a past president of the Indian Road Congress, was talking to this correspondent here on Monday.
He alleged that heights of most of these buildings were allowed to be raised by the GMC during this period, though the Guwahati Metropolitan Development Authority (GMDA) had restricted such acts. Unlike the GMDA, the GMC had no infrastructure to assess the structural designs of those buildings during that period, he said.
“Moreover,” he said, “during my tenure as the Commissioner and Secretary of the PWD, it was found that except its hill areas, the Guwahati soil had a load bearing capacity of 10 tonnes per square metre. The city soil is mostly alluvial. Such soil can allow maximum four-storey structures over isolated footings. Above that height, foundations with piling are required for the structures.
“We must take advantage of the geo-technical engineering, which is available nowadays in this part of the globe too,” he said.
In this connection, he reminded the recommendation made by the Dr N K Choudhury Committee that there should be an expert committee to examine the permissions granted to the high-rise structures by both the GMDA and the GMC.
He regretted that the models of public buildings built in other states have been adopted in Guwahati. This is very dangerous. As, the location of the city is under the high vulnerable zone-V so far its seismic vulnerability is concerned, he said.
He underlined the need to incorporate the findings and recommendations of the seismic mirco-zonation study in the GMDA master plan prepared for the city till 2025. “This is a vital issue concerning the life and property of the Guwahatians,” said the former PWD Commissioner and Secretary.
Moreover, he said, it is very important to immediately ascertain the building safety of all residential, public and commercial structures of the State and to ensure their quick retrofitting.
Referring to the Kobe earthquake of Japan that occurred at 5-46 am as per the Japanese Standard Time of January 17, 1995, he said that over 5,000 people had lost their lives in that earthquake due to the collapse of their own buildings. These buildings were constructed just after the Second World War, without applying the earthquake-resistant technology.
But the high-rise buildings of Kobe were not damaged by that earthquake, as, those buildings were built applying the modern technology. Quoting Toshio Mochizuki, the then head of the Centre for Urban Disaster Prevention at Tokyo and one of Japan’s leading authorities on earthquake-resistant measures, Lahkar said that the new Kobe buildings had come through reasonably well.
“That is why you have this interesting phenomenon that tall buildings are intact and smaller ones fall to the ground,” observed Mochizuki, Lahkar said.
It needs mention here that the January 17, 1995 Kobe earthquake had wrought heavy damage in the port city of Kobe. It lasted for about 20 seconds with a magnitude of 7.2 according to the old calculation and 6.8 as per the new calculation. Its depth was only 20 km below the surface. Many experts held this shallow depth of the earthquake and the weak structures of the old buildings mainly responsible for the catastrophe witnessed in Kobe.
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