New Delhi, July 19: Pillar number 67 of the under construction Metro railway track near Zamrudpur that collapsed on Sunday killing six people and injuring 15 is not the only one with a faulty design.
The two pillars on either side of Pillar 67, which gave way under too much weight last Sunday have also been found to be designed faultily.
These pillars – numbers 66 and 68 – have not developed cracks yet.
But experts claim that offering prop support to any cantilever pillar (inverted L-shaped pillars) is not the right practice.
“Originally the pillars were designed as portal pillars. Here the track will leave the median of the road and move to one side. So, its alignment is in a curvature. Hence, the viaduct on which the trains will run were to be supported by two pillars,” A senior professor of civil engineering said.
But the portal pillars were shelved in favour of cantilever pillars. Residents here were opposed to the pillars as they would have left little road space,” he added.
“The cantilever of Pillar 67 developed a severe crack as soon as the launching girder was put on it. Work was stopped for two months. An inquiry committee suggested providing prop support to the cantilever.
This is invariably dangerous. The same was suggested for pillars 66 and 68 also,” he said. The expert doubted the competence of the inquiry team.
“Temporary rectification measures can’t be suggested for long-term structures. The moment outside support was provided, it ceased to be a cantilever pillar and the distribution of axial forces changed.” “The two other pillars are also dangerous and their designing and capacity should be probed.
If the pillars can’t stand without prop support, the structures should be abandoned and new pillars should be erected. Else, there can be more mishaps.” Another expert criticised Delhi Metro Rail Corporation (DMRC) for not allowing thirdparty inspection at their construction sites: “World over, the set procedure is that a third party inspects civil constructions of this scale. But, DMRC had no such arrangement with. Only their signalling and electrical wiring is inspected by RITES.”
–Agencies