Structural collapse

Authors: Sayantan Bera (Kolkata), Soma Basu (Delhi), Akshay Deshmane (Mumbai)

A house in Delhi that had foundation for single storey fell after six storeys were added to it (Photo: Bobby)
A house in Delhi that had foundation for single storey fell after six storeys were added to it (Photo: Bobby)

Luck runs out

Mumbai Metropolitan Region
Lucky Compound, April 4, 2013

Lucky Compound proved quite contrary to its name. The residential building complex in Shilphata, 26 kilometres from urban Thane, near Mumbai, saw one of India’s biggest building disasters of recent times. Adarsh 1, one of the five buildings under construction in the complex, collapsed, taking with it 74 lives and injuring another 64. Mangal Patil, a witness to the tragedy, says it fell like a pack of cards.

“Construction of buildings had started just a couple of months back. Tall buildings sprung up within no time,” says Patil. That evening at around 6:30, seven floors of Adarsh 1 fell when people were inside them, he says. There were construction workers on the sixth and seventh floors, and the fourth floor had a tuition centre for children.

Thane municipal corporation demolished the other four buildings because they, too, were unsafe. A total of 21 people were arrested. Two of the seven builders were charged with culpable homicide not amounting to murder. Hira Patil, Nationalist Congress Party corporator, was suspended from his post and charged under Prevention of Corruption Act, 1988. The rest were also charged with corruption.

74 people died in a building collapse at Lucky Compound in Mumbai Metropolitan Region (Photo: Akshay Deshmane)
74 people died in a building collapse at Lucky Compound in Mumbai Metropolitan Region (Photo: Akshay Deshmane)

The Maharashtra government has not given the reasons for the collapse yet. But Alok Avasthy, commandant of the fifth battalion of the National Disaster Response Force (NDRF) who oversaw the rescue operations, says there were three fundamental causes of the collapse—use of substandard material, poor construction and flouting of norms.

“The land on which the complex was built was marshy. It required refilling before such a high structure could be built,” says Avasthi. Besides, the foundation was about three metres. This is not deep enough for a multistorey building, he says. Avasthy consulted civil engineers after the collapse and found the foundation should have gone around nine metres deep.

The builder had raised building within three months without giving cement the time to bind properly and attain the strength to hold the structure together. Concrete needs at least two weeks of regular watering before it can support load.

NDRF also found the walls extremely brittle. Very little cement was used. The walls were mostly of sand. The iron rods used in columns were extremely thin—less than 16 mm diametre—and may not have been able to withstand the structure’s weight, says Avasthy. The iron rods should have been at least 24 mm thick.

After the collapse, Chief Minister Prithviraj Chouhan admitted in the state Assembly that 90 per cent of the constructions in Shilphata are illegal and have been built on shaky foundations.

Destruction by fire

KOLKATA
Stephen Court, March 23, 2010
AMRI Hospital, December 9, 2011

An ICU patient is evacuated from AMRI Hospital, Kolkata (Photo: Reuters)
An ICU patient is evacuated from AMRI Hospital, Kolkata (Photo: Reuters)

Professors of architecture often tell their students a joke: “God is kind and concrete is strong, so go ahead and build”. Unless there are major goof-ups in the design and quality of material, concrete structures are safe, they say.

But what about fires? Kolkata, the third most populous city in the country, has brutally learnt that it is important for buildings to be fire-proof. Regular incidents of fire in public buildings have scarred the city in the recent past.

The bustling Park Street area, known for its posh eateries and pubs, bore witness to a crude sight. As rescue teams desperately searched for bodies charred by fire in the Stephen Court building, vultures hovered over the gutted structure. A short circuit had caused the fire. As many as 17 bodies of young call centre workers and residents of the building were found on the stairs leading to the terrace that was locked. The only emergency fire exit was also closed. The fire’s heat caused the fifth floor to crumble, burying people in the rubble. A total of 43 people died.

The heritage building was constructed in 1924. Two floors were added illegally in 1984. Later, construction was regularised after payment of a hefty fine to the Kolkata Municipal Corporation. Rules were flouted and offices were allowed in the building that also had residences. The offices used staircases to store material, blocking way to the terrace.

The fire minister of West Bengal, chairing the only such ministry in the country, had only one prescription—hydraulic ladders should be kept in and around Park Street to speed up fire-fighting. Clearly, the city administrators had not learnt their lessons. A year later, a devastating fire at the posh AMRI Hospital in south Kolkata claimed 93 lives. More than half of them were admitted in the intensive care unit. The fire spread when a stockpile of cotton in the basement caught fire due to short circuit. Smoke travelled through air-condition ducts, and patients and staff were gassed to death. The modern hospital’s air-conditioned building did not have an escape route for smoke. For two hours after the fire was detected, the hospital staff did nothing about it. They did not even call the fire department. The hospital had not done fire drills as specified in the National Building Code (Annexure E, part 4).

Himadri Guha, former civil engineering professor at Jadavpur University, Kolkata, and now a real estate developer, says fire safety is usually not incorporated in a building’s design. “What we have is an active system to douse fires,” he says. The fire department also lacks technical knowledge to assess fire hazards, such as inflammable building material and carry out fire audits. Escape signages even in big shopping malls are not properly placed, he adds. The department issues no-objection certificates to building plans solely on its fire-fighting experience. “In fact, it does not have an architect who can read drawings of a building. Qualified fire safety engineers who are expert in structural design of fire safety are the best people to issue no-objection certificates,” Guha says.

The Kolkata Municipal Corporation has declared 600 old buildings in Burabazar, in central Kolkata, risky. Between 2005 and 2006, nearly 100 people were injured in separate incidents when five buildings collapsed and 30 buildings caved in. As many as 500 buildings have been identified partially risky and need thorough repair. Most of them use inflammable material such as polythene and plywood to make partitions.

Building collapses are fairly common in the city. In 2011, an illegally constructed five-storey building collapsed in Nayabad, on the eastern fringes of Kolkata. Soon after, another five-storey building developed cracks and tilted in south Kolkata prompting the mayor to instruct the building department to scrutinise plans before sanctioning constructions. Over 3,000 old buildings have been categorised dangerous by KMC. God, it seems, is not kind these days.

Architectural disaster

DELHI
Lalitha Park, November 15, 2010

The building stood on the sandy Yamuna floodplains (Photo: Bobby)
The building stood on the sandy Yamuna floodplains (Photo: Bobby)

Seventy-one people died and another 200 were injured when a building collapsed in Lalitha Park on the banks of the Yamuna in East Delhi. Amritpal Singh built the house in 1988. It was single-storey then. In 1990, he added two storeys to it. By 2005, the building had reached five storeys. When it collapsed, it had seven floors apart from the basement. The building was supported by only walls. There were no pillars. About 200 tenants lived there. Three months before the incident, the basement, which was used as a storehouse, had been flooded with rainwater. Nothing was done about it.

Chandan Ghosh, head of the National Institute of Disaster Management (NIDM), stated in his report to the National Disaster Management Authority (NDMA) that structural fragility and blatant disregard of rules brought down the building.

The building stood on the sandy Yamuna floodplains. Monsoon floods led to seepages in the foundation. The guidelines of the Bureau of Indian Standards and the National Building Code of 2005 were not followed. The building had haphazardly constructed balconies and rooms, which were not sufficiently supported by beams and columns. Irregular pattern exerted disproportionate pressure on the already weak foundation. The 0.3 square metre foundation meant for a single-storey house had become insufficient.

In its 296-page report that was tabled in the Delhi Assembly, a commission of inquiry set up under retired judge Lokeshwar Prasad pointed out a litany of lapses by the Municipal Corporation of Delhi (MCD). Poor coordination between different departments of MCD, entrusted with licensing and monitoring, was blamed for the collapse. The corporation also charged Delhi Development Authority with approving Zonal Plans and allowing multistorey buildings on floodplains without proper checks. Electricity provider BSES Yamuna Power Limited was hauled up for giving two commercial connections to a residential unit. The Delhi Police was blamed for not acting on complaints of illegal construction.

The building collapse temporarily shook the civic authorities out of slumber. Three buildings in the neighbouring Laxmi Nagar area were evacuated. MCD directed evacuation of 35 more residential buildings. But three years on, with no alternative, the residents are back into these buildings.

Grease, grit and grime

Bribery is the norm in the construction sector. Since clearance is a long-drawn process, developers take the easy route; they pay big bucks and flout all rules

People still live in century-old buildings in North Kolkata that may collapse any day (Photo: Sayantan Bera)
People still live in century-old buildings in North Kolkata that may collapse any day (Photo: Sayantan Bera)

G R Khairnar, former deputy municipal commissioner of Mumbai, is infamously called the Demolition Man in the city’s real estate circuit. In the 1990s, he took on underworld don Dawood Ibrahim and decided to demolish 200 illegal buildings owned by the gangster. “I was given the post because there was a huge public outcry against illegal structures,” says Khairnar.

But he could demolish only 30 of them. “The chief minister and the municipal commissioner started putting pressure on me to stop the drive,” he says. When he paid no heed and demolished the 30th building too, he was suspended from duty. Khairnar has seen corruption and lethargy in the building clearance system up close and personal. “The clearance system encourages corruption and violations,” he says. No-objection certificates (NOCs) are issued only after bribes are paid. “Otherwise, applicants face inordinate delays,” he adds.

A developer at Kolkata who did not wish to be named shares his experience. While constructing a three-storey building in a business hub of the city, the local elected councillor of the Kolkata Municipal Corporation (KMC) asked him, “Why not add two more floors? I am there to help you”. Had the developer agreed, he would have had to pay at least Rs 1,000 for every square foot (1 square foot equals 929 square cm) constructed illegally. “Here, property sells at Rs 10,000 per square foot,” he says. His refusal, however, meant his building plan did not get the completion certificate.

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The key to prevent building collapse is monitoring. But it’s difficult while inspecting extensions to existing structures. Multiple owners of the structures complicates the problem.

Building foundations are designed to carry specific loads and require symmetry. Addition of extra floors, balconies, rooms over the original design puts pressure on the building structure. Removal of walls, columns and beams for renovation can severally weaken its frame. Legally, any alteration requires approval from the authorities, but rarely does one obtain them. The practice is to quickly make the changes before the civic bodies notice.

Building hastily is an equally risky proposition which leads to tragedies like the one in Thane. Strengthening the foundation is usually not done for convenience. Concrete, too, is not given adequate curing time of at least three weeks to set and gain strength. Therefore, the structure’s capacity to carry load decreases. Besides, decisions like increasing floor area ratio, or the number of floors, accommodating car parking, regularising illegal modifications often complicate the safety concerns.

Old buildings are a different kettle of fish. Buildings that have outlived their designed lifespan are more susceptible to structural failures and fire hazards. Since the buildings are a city’s heritage, their owners are barred from altering them drastically to put them to modern day use. Old Delhi has many such buildings that require repair, says an MCD official. Rains make these buildings more hazardous for residence.

“We cannot evacuate them because they have no place to go. We have no money, nor the infrastructure to deal with such dilapidated buildings,” adds the official. To ensure public safety, incentivising their maintenance is a must.

The problem extends to construction quality in state-of-the-art structures. False ceiling collapse in the renovated Jawaharlal Nehru Stadium before the 2010 Commonwealth or the faulty civil works of Airport Express metro line, are recent examples.

The malaise in the construction sector runs across the country. Down To Earth approached a small-time builder at Kalkaji in Delhi, posing as a house owner who wanted to increase the floors. “How many floors do you want? We have our own set of architects who get the plan sanctioned. They are all registered with the Municipal Corporation of Delhi (MCD),” he said. Clearance for a building on 600 square feet area requires between Rs 10,000 and Rs 2 lakh, he says. Obviously, the amount would increase with increase in the number of floors and extensions. “Once MCD sanctions the plan, minor changes would be easy. Who verifies the size of the rooms!” he says.

It’s not just small-scale builders flouting norms; land grab is rampant with big builders, too. Alaknanda Community Centre in Delhi will soon see a sprawling mall in 7,20,000 square feet area. The land was originally marked for community activities and sports facilities by the Delhi Development Authority (DDA). “Our elected representatives have not objected to it. Lack of transparency in the deal and its clearance is shocking,” says Ashutosh Dixit, who is leading the protests against the mall.

Convoluted clearance system

There are certain clearances every builder has to take. But the system is anything but simple (see ‘Tedious clearance process’).

Mumbai has one of the lengthiest clearance systems. Thirty-five to 40 NOCs from various agencies are required to obtain approval for a building proposal, says Shirish Sukhatme, president of city-based Practising Engineers, Architects and Town Planners Association (PEATA). Depending on the location and size of the project, NOCs may be needed from the railways, heritage committees, coastal and environment bodies of the Ministry of Environment and Forests, and the state government. This can escalate the number of NOCs to 65.

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Various agencies provide NOCs with an expiry date of 60 days. If the Brihanmumbai Municipal Corporation (BMC) does not give clearance within this time, all the NOCs have to be procured again, says Sukhatme.

BMC’s building proposals department handles most of the construction plans. The proposals are first scrutinised by a sub-engineer and then by an assistant engineer in charge of survey. The next to see the file is an executive engineer and a deputy chief engineer. Projects exceeding 2,500 square metres in suburbs and 600 square metres in city have to be referred to chief engineers of the building proposal and development plan departments. The proposal is finally cleared by the Municipal Commissioner.

“Proposals rarely get rejected outright. In most cases, architects rework plans according to the requirements of the Development Control Regulations (DCR),” says a PEATA member. “The developer then applies for concessions in regulations to the Municipal Commissioner,” he says. At times, these concessions help builder flout rules. For instance, Palais Royale in Worli managed to get clearance to build a 75-storey residential apartment. In 2011, BMC issued two stop-work notices to the developer. When BMC did not get a satisfactory response, it served the developer demolition notice. But construction carried on and reached 56 floors. In 2012, non-profit Janhit Manch filed a public interest petition in the Mumbai High Court alleging that the floor space index (FSI) granted for the building was much beyond what the rules permitted. On May 14 this year, the court ordered the builder to stop construction and asked BMC to recalculate the building’s FSI.

Civic body officials deny laxity. A senior BMC official says in 2012, Subodh Kumar, the then municipal commissioner, had modified the DCR to ensure time-bound approval of building proposals. Besides, the civic body filed an affidavit in May this year through deputy municipal commissioner Anand Wagralkar, stating that all unauthorised constructions will be issued stop-work notice under Section 354-A of the Mumbai Municipal Corporation Act. BMC chief Sitaram Kunte says, “Survey of dangerous buildings for this year is complete. We have demolished some structures.” Since 2008, BMC has found 1,023 illegal constructions and demolished 620.

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In Kolkata, clearance is not an issue. The logic is simple: commit the crime and get the illegalities regularised by paying penalty. To make legal additions to an existing building, the owner needs to submit nearly 35 documents that include NOCs and affidavits. If any deviation from the plan is found, the owner is harassed by threat of demolition and demand of bribe. The usual practice is to get it regularised by paying fine. For residential properties, regularisation charges are four times the sanction fee charged per square foot. For commercial properties it is eight times the fee.

The Kolkata Municipal Corporation’s (KMC) building rules were framed in 1923. “Till 1960s, there was an attempt at urban planning under the Kolkata Improvement Trust,” says Dilip Chatterjee, junior vice-president of the Indian Institute of Architects. “Today, architects employed in the building department of KMC have nothing to do with urban planning.”

Absence of urban planning and lack of space have led to organic growth in unauthorised constructions. In 2012, KMC sent over 1,000 notices for unauthorised construction. It collected Rs 50 crore in penalties, up from Rs 30 crore a year earlier. The cases are heard in KMC by a hearing officer who can be a retired judge or a civil servant.

“During the hearing no competent officer of KMC appears to fight for the demolition of structures,” says Chatterjee. In case the verdict goes against unauthorised construction, the offender can appeal to the municipal building tribunal. If an owner wants to make additions to his building legally, he would be at the mercy of junior officers.

Rajat Banerjee, a Kolkata-based architect, says that upstart, fly-by-night developers severely compromise on quality. Kolkata’s building by-laws are unique; they do not require a licensed architect to design building up to five floors. In 1976, the West Bengal government made it mandatory that trained architects should design buildings. But the Licensed Building Surveyor (LBS) lobby stymied the effort by going to the Calcutta High Court. The case is yet to be disposed of. Anybody with a diploma in civil engineering can become an LBS.

A developer Down To Earth spoke to said that on the fringes of Kolkata, in localities like Behala, Dum Dum and Garia, 700 square feet residential apartments are sold for as low as Rs 15 lakh. This translates to a little over Rs 2,100 per square foot. Standard construction costs at least Rs 1,500 per square foot. Add to this grease money, sanction fee and the developer’s margin. Then, one cannot account for the price of land. “Obviously, substandard building material is used to corners. Plasters peel off or cracks appear within months of construction. Cheap wiring will also make these apartments potential tinderboxes in future,” says the developer.

Anandiya Karforma, director general of the building department of KMC admits to the provocation to construct illegally. But it is specific to certain pockets of Kolkata, he says.

Rules bent, safety compromised

Over the years, building rules have been diluted to unsafe levels. For instance, under the Calcutta Municipal Act of 1923, no building was allowed if the road in front was less than 30 feet wide. By 1980, this was changed to 10 feet. The building rules of 2009 say one can construct a two-storey building in front of a four-feet wide road subject to the approval of the mayor in the council—the elected body. Thus, it is fairly common for the bride to walk to her new house after marriage leaving the hired car a kilometre away. “This has set a dangerous trend. It compromises safety and puts pressure on other facilities such as sanitation and water supply,” says Chatterjee.

“Safety is not so much the character of a structure but what you expect from it,” says Laurent Fournier, a Kolkata-based architect specialising in eco-sensitive constructions. “A commercial enterprise in what was designed to be a residence can increase the weight of the building. This is what happened recently in Bangladesh when heavy machines of a garment factory brought down a building,” he says.

Fournier warns of another danger. Most apartments are not earthquake-resistant and do not follow the weak beams, strong column principle. “We have failed to learn any lesson from the Gujarat earthquake,” he says. All metropolitan cities in the country fall under moderate to high-risk seismic zone.

“The geo-tectonic situation is changing,” says Himadri Guha. The Deccan plateau is pushing northern India and the Himalayas. The developing stress will release itself from time to time. “In Kolkata, we are sitting on a volcano stock of old buildings,” he says.

The situation is no different in Delhi. It would not take a visionary to estimate the magnitude of a catastrophe if a moderate earthquake strikes the city. Ninety per cent of the building designs in the capital are either by the mason or the contractor. Newly constructed houses rarely abide by the meticulous National Building Code-2005, Master Plan of Delhi-2021, Vulnerability Atlas-2006, Building By-laws, or the housing construction, planning, development and regulatory authorities. The seasonal wear and tear demand is rarely met.

The Tejendra Khanna Committee of Experts, set up in 2006 to look into various aspects of unauthorised constructions and misuse of premises in the city, found that 70-80 per cent structures had violated Building and Development Control Regulations. It stated that the formalities required to obtain a building completion certificate or even a building plan sanctioned is tedious, so owners seldom procure them.

In April 2011, the Delhi government made it mandatory for all builders to submit sanctioned building plans along with structural safety certificates for their new buildings. Within days, the number of applicants for property registration saw a drastic fall. Ten days later, MCD informed the government that it did not have enough engineers to issue the certificates. The order was revoked.

“Leave alone structural experts, there is no sense of accountability in engineers and architects who play the most important role while approving the building plan of any proposed building,” says Chandan Ghosh, head of National Institute of Disaster Management.

http://www.downtoearth.org.in/coverage/structural-collapse-41201

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