It took a string of building collapses during September-October for the civic authorities in Bengaluru to wake up and start counting unsafe buildings. A survey revealed 404 buildings in dilapidated condition while another 300 much newer ones were judged as vulnerable to collapse. The revelation is a wake-up call on structural safety norms being thrown to the winds during construction. Besides, the lack of timely maintenance has rendered many older buildings ending up in dilapidated conditions. But some of these are still inhabited by people oblivious to the danger of the roof coming down on them or the very foundation giving way.
The problem is not restricted to Bengaluru alone; it is rampant across the state. Just how callous approaches give birth to a threat that can be easily avoided is observed through this case in Udupi. A private firm, BR Life Company, owned by business tycoon Dr B R Shetty, had taken up construction of a high-rise building for a super-specialty hospital near KM Marg in the heart of Udupi. But the plan gave safety a go-by while attempting a three-level basement structure in violation of the zoning regulations of Udupi Urban Development Authority.
The construction did not take off — more for financial reasons than enforcement by the authorities. But they had already dug a 60-foot-deep pit for the three-level basement and the foundations more than two-and-a-half years ago. Today, the pit, left unattended, poses a serious risk to adjacent buildings — including a high-rise hotel.
The owner of the hotel building has already complained to the Udupi City Municipal Corporation, which does not seem to have understood the seriousness of the issue, he says. Corporation Commissioner Dr Uday Shetty says a notice has been served to BR Life Company to fill up the pit as it poses a threat to adjacent buildings. With heavy rains in the region, the structures adjacent to the huge pit face a major threat.
NO LESSONS LEARNT
Interestingly, lessons from Bengaluru have not been learnt elsewhere. For instance, in spite of frequent earthquakes in the Vijayapura region, no survey has yet been conducted to identify buildings prone to collapse. In the last one-and-a-half months, at least 11 tremors measuring between 1.4 and 3.9 magnitude on the Richter Scale have been recorded. As no damage to structures were reported in any part of the district, Vijay Makalaki, Commissioner, Vijayapura City Corporation, says, “We have not identified any buildings that are in a dilapidated stage. No complaints regarding such buildings have been received. But a special survey will soon be conducted to identify such buildings in our jurisdiction.” In Vijayapura, builders hardly follow procedures. Although Vijayapura city does not have an apartment culture, one can find hundreds of buildings taller than two storeys. “Awareness will be created among the people in the city. A special task force will also be established to address emergencies like building collapse,” Makalaki says.
Srinivas Reddy, senior geologist and former director of Karnataka State Natural Disaster Monitoring Centre, says, “There has to be integrated work from geologists and soil and structural engineers before construction of every building. There are certain procedures, like verifying soil strength and identifying borewell points, that need to be carried out while constructing buildings. A majority of the people ignore these norms as these add to expenditure.”
Reddy cautions that especially in the seismic zones, buildings have to be earthquake-resistant. “There are high chances of buildings collapsing when tremors of magnitude above 7 on the Richter scale occur. If buildings are not developed as per norms, they can still be strengthened through retrofitting,” he explains. “It is also the responsibility of local administrations to verify designs of each structure by geologists and structural engineers before approving the construction,” says Reddy. The National Building Code is comprehensive on how buildings should be designed for earthquakes and it is a requirement by law that the code has to be followed, but because of high construction costs, people cut corners and do not follow the code entirely, resulting in unsafe structures, says Praveen Bavadekar, noted architect in Belagavi. “Our corporations do not audit structural designs of buildings the way they look at FAR (Floor Area Ratio) or setbacks (spacing between neighbouring buildings). Introduction of such a design review may be one of the ways we can make safer buildings,” he says.
Comprehensive structural audit of buildings constructed by the unorganised sector is necessary for safety, says Bavadekar. He says while the building industry is regulated to a large extent by corporation bye-laws and such buildings do not have structural issues, “there is large-scale construction happening and we have no way of knowing about their safety unless we do a comprehensive structural audit of such buildings.”
In March 2019, a building collapsed on Belagavi Road in Dharwad, killing 19 people. The building collapsed due to poor quality works and unscientific planning. During a survey by Hubballi-Dharwad Municipal Corporation (HDMC), another residential apartment was found to have poor quality work and it was reconstructed in 2019.
Construction should commence after proper permission by the departments concerned. Soil testing and building stability engineers should be involved. The officials concerned should act properly before granting permission, said an expert. A proper audit of the soil and the site is, therefore, mandatory before construction and at regular intervals after the building is occupied.
Improper rainwater harvesting can affect a building: Expert
Prof M B Rajegowda, agrometeorology scientist and former registrar, University of Agricultural Sciences, Bengaluru, says improper adoption of rainwater harvesting measures can cause multi-storey buildings in urban areas to tilt and can be an increasing cause for concern as the concept becomes more popular. He explains that due to lack of knowledge, inadequate facilities, or financial constraints, most building owners or associations follow the easiest method of digging rainwater pits/sinks within their own compounds. This causes micro-water lanes in the undisturbed soil flow in various directions.
In such cases, water seeps into the deep soil underground. The soil gets wet and loses its original binding strength/capacity below the building or even the adjacent buildings. Due to the reduced load-bearing capacity of the soil, the foundation bed or pillars of the building sink. If any of the building’s columns is subjected to such wetting of the subsoil, the reinforcement is affected and cracks develop between beams, causing damage or tilting of the building.
(With inputs from Chetana Belagere & Ashwini M Sripad in Bengaluru; Tushar Majukar in Belagavi; Prakash Samaga in Udupi; Mahesh Goudar in Vijayapura; Divya Cutinho in Mangaluru and Mallikarjun Hiremath in Dharwad)