There is a big difference between illegal buildings and poorly constructed high-rise buildings. Not all illegal homes are weak and a weak home, whether it is legal or illegal, is prone to collapse. Along with breaking the law in illegal housing, there is also a tendency to violate technical rules and regulations.
Big house in Municipal areas of Kolkata refers to a four-storey to a ten-storey house. A Licensed building surveyor (LBS) or architect, a Structural Engineer, and a Geotechnical Engineer are required at the time of design approval for these houses. LBS prepares the practical design of the house, a Geo-Technical Engineer looks after the foundation technology and a Structural Engineer ensures the overall structural stability of the house.
The supervision and regulation of the project should be left in the hands of the engineers, but unfortunately most of the builders and promoters of Kolkata and around, knowingly or unknowingly, move away from these engineers after the design is approved by the municipality. Many people don't even know the engineer who signed the plan.
Some builders again fall into the hands of masons posed as engineers or some people who pretend to know everything, As per their advice, developers do not think about hiring technical personnel and forget to check their biodata and educational qualifications.
But the builder has to suffer the consequences. Many, though willing, do not realize that their house is weakly built in the absence of the right mentor. The house is not earthquake-proof, and the foundation of the house is not stable enough.
Cast-in-situ concrete piles are to be done to bear the loads from the building, when soil tests show low capacity, or in the case of large houses it's generally required. This pile foundation transfers the weight of the house to the solid soil far below the surface. Instead of reaching this hard ground level, some builders reduce the depth of the pile which later becomes fatal.
It is now mandatory to make the house earthquake-resistant. For this, several criteria have to be followed. Branded ductile iron and branded cement should also be used. Non-trade cement should not be used in this case. A few promoters are very conscious of following all the rules. Houses made by them are durable and strong.
We, engineers, cannot avoid the responsibility for a weak multistorey. Most of the engineers are very busy, they don't have time to check the work. They earn by signing the plan and think that the responsibility is over. It is the engineer's responsibility to create awareness and to properly convince the builders to construct a durable structure. Eventually, the builder will show interest in good work and the engineer will lead the way, that's how it should be. Only then will the number of fragile houses like the building collapse at Garden Reach, Kolkata, and innocent lives be spared. The house should not be illegal, but it should not be weak at all.
(Image is used only for representation purposes)
