Faulty soil analysis may be the cause

Chennai: Top civil engineers and builders point out that a faulty soil analysis could be behind the shocking collapse of a 11-storey apartment complex at Porur that crumbled during heavy rains on Saturday.

Structural engineers point out that a soil test and the load-bearing capacity of soil needs to be checked, even for a single-storeyed building, whereas it was not yet clear whether these were done on the building that collapsed.

Prof M. Sekar, a civil engineering professor and formerly dean of Anna University’s College of Engineering, Guindy, says that every building needs to be checked for soil stability, which plays a vital role in building construction. “One also has to check the soil’s load-bearing capacity, even for a one-storey building. We also need to look at the structural design,” he said.  The National Building code says that soil samples from representative locations on the site and study area should be collected and analysed for important relevant physical and chemical parameters. “Soil monitoring should be carried out in at least three locations, including one at the project site,” the code further says.

Informed sources in the builders’ circle allege that both the Chennai Metropolitan Development Authority (CMDA) and Chennai corporation do not insist on a soil testing report from a geo-technical surveyor which is being done in other states.

“Nobody knows who certifies these buildings without proper soil testing,” a city-based builder said.

Confederation of Real Estate Developers’ Associations of India (Credai) representatives here said that the builder of the collapsed building, Prime Sristi Housing Properties Ltd, was not members of the apex body.   Credai usually enforces a set code of conduct and members are expected to adhere to procedures, which also enlists rules related to quality of construction and materials used in building.

“Today’s collapse seems primarily because of a faulty soil analysis,” said a senior Credai member who did not wish to be named. “The building seems to have come up near a lake, which may have undergone a land fill. And when the foundation is usually laid till the rocks are hit, this could have misled engineers, resulting in the sinking of towers,” he added.

“Though, usually, the quality of construction materials is blamed for a building collapse, in this case, it seems more of a structural engineering problem owing to improper soil analysis leading to faulty design,” said another civil engineer with a leading developer.