Did cost-cutting cause Prestige building collapse?

Did cost-cutting cause Prestige building collapse?

Divya Gandhi

Steel centring system was overused, says committee’s preliminary report

Report rules out faults in structural design

Safety of remaining structures not yet established

— Photo: Bhagya Prakash K.

What went wrong: A file picture of a block under construction at Prestige Shantiniketan in Whitefield which collapsed on October 23, 2008.

Bangalore: The collapse of the 16-storeyed apartment block under construction at Prestige Shantiniketan in Whitefield last October, killing one construction worker and grievously injuring four, could have been avoided had the builders invested in upgrading some overused equipment, suggest the findings of an investigation into the accident.

The steel frames used during construction collapsed due to “overuse” causing a “cascading effect” from the upper floors to the bottom ones, according to a preliminary analysis by a committee appointed by the Bangalore Development Authority (BDA) to look into the incident. The report will be finalised by various members and submitted to the BDA next week.

“Failure of the centring system” of which the steel frames are a part is “the most probable reason” for the collapse, stated the report, which has ruled out faults in structural design, quality of construction, ground settlement or grade of construction material, some of which were earlier speculated.
Time factor?

The steel frames and steel moulds that support the cement till it dries are often used several times over — well beyond their lifespan — as they are expensive to buy afresh for each project, explained a civil engineering expert on the case.

“A newly bought centring system can cost as much as 20 per cent of the cost of building an entire floor. The steel systems can be used safely about 10 to 20 times depending on the quality of the product,” said the source.

It is also possible that the builders were in a hurry to complete the project, therefore overlooking the need to replace the infrastructure. A defective or old centring system grossly compromises the safety of construction workers.

“When the cement is green (wet) and the steel support is also unstable, the workers are most vulnerable,” the source explained.

Eyewitnesses had observed that the structure, “Tower C”, one of 25 such towers, took around 50 minutes to collapse.

Over 100 construction workers, including women and children, were present at the construction site when the accident took place on October 23, killing a 23-year-old worker from Orissa, Munna Katua.

The safety of the remaining structures has not yet been established.

The report added that the other aspects of design, engineering and architecture of the building were found satisfactory.

The structural design has been carried out in a “methodical way”; all the relevant Codal provisions including earthquake provisions have been adhered to; and the reinforcing bars and readymix concrete are “satisfactory and as per design norms”, the report stated.