The Palarivattom flyover that was constructed to last for at least 100 years would become fully dysfunctional in 20 years. However, there is no need to demolish the structure as its foundations are solid and intact. These were some of the observations of the expert panel headed by E Sreedharan to look into the structural defects of the flyover.
The study also said that the flyover could be restored in 10 months at a cost of Rs 18 crore. The flawed structure was originally constructed for Rs 42 crore.
The flyover had developed cracks within three months of its commissioning in 2016. The LDF government had deputed Delhi Metro Rail Corporation principal advisor E Sreedharan to conduct a study on the bridge on June 17.
“The study has found grave irregularities in the construction of the bridge,” Chief Minister Pinarayi Vijayan said after a post-cabinet briefing here on Friday. Sreedharan had submitted the expert committee's report on July 4.
The Chief Minister said that a bridge should normally last for at least 100 years. “But the expert committee has found serious defects that give the structure a life of not more than 20 years. In fact, it has become useless in two-and-a-half years,” Pinarayi Vijayan said, briefing reporters on the contents of the Sreedharan report. It was on May 1 that traffic was banned on the bridge.
“The bridge has 102 RCC (reinforced cement concrete) girders. Cracks have developed in 97 of them. The study report says that it is difficult to assess the intensity of the cracks as a special type of paint has been applied on these girders,” the Chief Minister said, “The concrete used is of low quality,” he said.
The problem begins right from the start, right from the structure's design. “The study found problems with the structure's design also. Cement and steel were not used in adequate quantities. So it was found that the concrete did not have the necessary strength. The beams are unsteady. They are almost fully damaged,” the Chief Minister said.
There are visible cracks on 16 of the 18 pier caps of the bridge. “Three of them are in an extremely dangerous condition,” the Chief Minister said. “The study has said that all pier caps should be bolstered using concrete jackets,” he said. The 17 concrete spans, which have been found in a dangerous condition, will have to be restored using pre-stressed girders.
The weakness of the concrete was assessed by conducting the ultra sound pulse velocity test on various parts of the bridge. “It will take ten months to restore the bridge,” the Chief Minister said.
Besides Sreedharan, the expert committee included Chennai IIT Prof Alaga Sundaramoorthy, concrete technology and bridge design experts Mahesh Tandon and Shine Varghese, National Highways chief engineer M Ashok Kumar, and the PWD chief engineer S Manomohan.
The Chief Minister said that the PWD had been asked to initiate follow up measures on the basis of the study report. A Vigilance probe into the irregularities in the construction is already on.
