It was not only the structural auditor who erred in the case of the collapsed foot overbridge (FOB) at Chhatrapati Shivaji Maharaj Terminus in March, which killed seven people. An inquiry report into the matter has also blamed a contractor, already blacklisted in a road scam, for poor work on this bridge in 2012-13.
The collapse of Himalaya Bridge prompted the Brihanmumbai Municipal Corporation to order a detailed inquiry into the matter. The report, submitted by the vigilance department to former municipal commissioner Ajoy Mehta last week, has also blamed RPS Infra projects Pvt. Ltd. for the repairs it undertook on the bridge in 2012-13.
The report states that the shoddy repairs resulted in peeling of epoxy paint, “as observed on the debris of the super structure deposited in the godown.” Structural repairs were carried out in 2012-13, and were apparently “improperly executed.”
Similar to the primary report, the second report has also come down heavily on the auditor firm Prof. D.D. Desai Associated Engineering Consultants and Analysts Pvt. Ltd.
While the auditor has pointed out corrosion in the reinforcement of slab, “no test on the concrete deck slab is conducted.”
The auditor was supposed to, as recommended by sub-contracted firm Geo Dynamics, do a comparison with original drawings for determining the reduction in thickness and whether further repairs or strengthening of the structure were required. No such action was taken by the auditor. The auditor also did not carry out tests to do an analysis of footfall vibration “to relate defects in the FOB to changes in its dynamic characteristics.”
While not carrying out a structural audit in a comprehensive manner, the auditor concluded the FOB was in good condition. “He overlooked his own observations to monitor the next inspection in case of corrosion and other defects as per his 2016 report,” the report said. “Due to black-and-white photos in the audit report, floor beam arrangement and other findings in the audit report were not clear,” it said.
However, the report has also admitted that the bridge had not shown any signs of collapsing.
“There appear to be no pre-failure symptoms that developed or were observed since no such information or complaints were received from users of the FOB immediately before the collapse. No distress or deformation in structural steel appears to be developed or observed before collapse. Thus, it appears that the collapse is a sudden structural failure.”
After virtual inspection of the bridge’s debris, the team observed that the structural steel is corroded, due to which thickness of its structural steel members is reduced.
Contrary to concerns that the role of the ‘A ward’ office that had undertaken beautification of the bridge recently, was not scrutinised, the report has made remarks about the ward. “During the work of refurbishment and painting of the FOB undertaken by the ward office, the existing flooring was removed and granite slab flooring was provided. This has resulted in additional dead load on the FOB,” the report says about the ward office’s work.
It has also come down heavily on the bridges department, saying its maintenance manual and circular was “not followed in toto with respect to periodic inspections and repairs of FOB.”
The report said the department’s executive engineer did not scrutinise the audit report properly, and accepted the recommendation. Also, the department never responded to the A Ward letter giving intimation of its beautification project.
The report further said that refurbishment was started without obtaining the bridges department’s remarks, and the ward’s executive engineer too went ahead with approving the estimate.