Jadavpur University will probe the collapse of a portion of the VIP Road flyover over the next 45 days while IIT Kharagpur will study the design and drawing of the structure to identify possible flaws.
The government’s formal request to start a probe reached JU on Tuesday, more than 48 hours after the collapse of a flyover inaugurated barely two years ago.
“JU has told us they will take at least 45 days to submit a report. They will have to conduct multiple laboratory tests. They will also take some equipment to the site for the probe,” said an official of the Calcutta Metropolitan Development Authority (CMDA), which had commissioned the flyover.
Professors Arup Guha Neogi and Dipankar Chakravorty, both from JU’s civil engineering (structural) department, will conduct the probe. The duo had a lengthy meeting with engineers of the CMDA before a visit to the crash site. “We have asked for the design document,” Guha Neogi said.
Urban development minister Firhad Hakim said the government had requested IIT Kharagpur to separately study the design and drawing of the flyover. “We have emailed the request,” he said.
According to a veteran civil engineer, a drawing is “a mathematical calculation sheet” that determines the plan of a structure. “The position of a slab or where to place a rod are specified in the design.”
While the two investigations will be independent of each other, the primary responsibility of identifying the cause of the collapse lies with the JU team.
State-owned company Mackintosh Burn had built the flyover based on the design provided by Consulting Engineering Services.
The CMDA has requested the JU team to focus on three areas — the cause of the collapse, the structural condition of the flank that was reopened to traffic a day after the incident and the technicalities of rebuilding the damaged portion.
The JU team is likely to submit a report to the CMDA in a week on how to remove the collapsed portion of the flyover from the canal.
“We need to rebuild that part of the flyover as early as possible and the JU team’s suggestions would be crucial to the process,” a source in the CMDA said.
Engineers say determining the speed limit for vehicles taking the flyover would be as important as finding out why a portion collapsed just as a marble-laden truck had crossed the curve of the Bypass-bound flank early on Sunday.
The CMDA has pegged the speed limit on the undamaged flank at 30kmph but is open to revising it, based on what the experts recommend.
“A flyover is built for quick commute, so a 30kmph speed limit may not be ideal. We want the JU professors to tell us what the speed limits should be on different portions of the flyover,” a CMDA official said.