: Kochi Metro trains will zoom through a path-breaking 90-metre-long balanced cantilever concrete span that will come up diagonally over railway lines at Ernakulam Junction railway station by 2017 end.
The structure would connect the metro viaduct from near the main entry of the station and Karshaka Road located near South Overbridge’s underpass. The stretch is part of metro’s phase 1-B extending between Maharaja’s College Ground and Pettah.
“Such a lengthy span is rare in any metro-rail system in India. It was decided to have the span having no pillars beneath since there is hardly any vacant space between tracks for erecting pillars.
It is even more an engineering challenge since the span is located at a curve having a 152-metre-long radius,” DMRC sources said.
The span will be constructed by S P Singla Constructions that has expertise in the field. The 90-metre span will be balanced on either end by 65-metre-long concrete spans, taking the total length of the structure to 220 metres.
Such spans are generally made for overbridges carrying vehicles. It has to be smoother and without undulations for the metro rail.
A hydraulic rig was deployed at Karshaka Road on Friday to begin piling for the structure. Another rig will be deployed within a fortnight near the railway station’s main entry, DMRC sources said.
Speaking of the innovative structure, P K Aravindan, who retired as professor in structural engineering from IIT, Chennai and is currently heading a prominent civil consultancy firm in the city said that balanced cantilever structure ensures saving of around 20 per cent funds as compared to conventional alternatives. “Long spans are ideal at centre of flyovers too since they make it possible to have a roundabout beneath,” he said.
