Mind the Criminal Gap
The collapse of the Vivekananda Road flyover in Kolkata last week has raised many serious issues for the consideration of technocrats and politicians. An inquiry has already been ordered by the West Bengal government to find out the causes of bridge failure. It is expected that the outcome of such findings would be effective for formulating future guidelines of construction of elevated roads in congested cities like Kolkata and suburban areas.
It is relevant to note that Kolkata, even though a ‘megacity’ — a metropolitan area with a population above 10 million — contains only 6.5% of its area as road space. This is too low a figure to accommodate the growing transportation needs of urbanisation. Therefore, the demand for constructing elevated roads in the city is real and will increase in the future to improve intracity travel and transportation.
With this backdrop, the construction of flyovers needs to happen both at a quicker pace as well as in a safer mode using modern engineering and management skills. The immediate response of the construction company that was responsible for the Vivekananda Road flyover after it collapsed was that it was an “act of god”. But domain knowledge in the field of engineering should reveal that the fault lies in the business of men and men only. It was a man-made disaster.
In the absence of adequate engineering data, some relevant questions can be raised. The project started in 2009 under the administrative control of the Kolkata Metropolitan Development Authority (KMDA) with a completion period of about two years. But after 65 months, only two-third of the total 2.2-km length of the flyover was completed, with several revisions of project completion time.
The delay appears due to change in the alignment of the bridge’s superstructure and underground utility services that were made a part of socioeconomic and political pressures along with financial and managerial problems faced by the contractor. Under these circumstances, the intervention of the government to complete the project faster became visible only when assembly elections were knocking at the door. The contractor was asked to finish the remaining 24% of the project within seven months only.
Hardly a proper root-cause analysis was done to revise the changed target date for project completion. And therein lies the important question: how was the contractor, classified as a chronic defaulter, deemed to have been capable of completing the project with a sudden project acceleration while adhering to quality management in a sensitive infrastructure project within a core city area? The question now becoming more relevant is whether the main contractor, IVRSL, subcontracted to a competent vendor who bothered to abide by the regulations to finish the project in time.
The issue of project supervision in this case became significant when an injured construction worker reported that during the initial period of concrete casting, a bolt from a pier of the bridge was found to have come out from a joint. This was readily welded by the technicians on-site and the concreting work was restarted immediately. This was a self-destructive step.
The supervisors should have realised the gravity of the engineering problem, a clear indication of the failure of the joints in the system as a whole. The decision to go ahead and weld the joints was wrong and should have been avoided at that stage.
It also appears from the photographs that the twin arms of the damaged pier buckled owing to structural or material failure under its own weight during construction. The possible reason for such distress could have been inadequate strength of the steel section where the pier meets its arms. It could have also been due to the shearing of bolts at joints. So, the strength of steel used in the pier and the inadequacy of joints may be major factors for the disaster.
The forensic investigation includes the design detailing of structure, the quality of construction material, the project management and supervision issues. Besides the engineering issue, the financial implication of project delay should also be kept in mind. Major delays in project execution result in a huge increase in the cost of materials, manpower, plants and equipment. The contractor of the doomed flyover project, which was delayed for six years, may have tried to compromise with the materials and supervisory manpower to optimise execution cost.
The government and its nodal agencies must be attentive to avoid delays in project execution to save public money in wasteful cost head as the escalation of the project value and the risk to lives of people can be minimised.
The writer is professor, department of construction engineering, Jadavpur University, Kolkata
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