A distress crack of up to 3 mm width was reported in the shear zone on both sides of a girder in the approach span of the Vyttila railway overbridge on the Edappally-Aroor NH 66 Bypass corridor, according to a report submitted to the National Highways Authority of India (NHAI) by a firm deployed by the Union Ministry of Road Transport and Highways (MoRTH).
The crack was detected on September 20 by a Mobile Bridge Inspection Unit (MBIU) of the firm which analysed the condition of bridges on national highways in the State after the August floods.
The firm that conducted the inspection for MoRTH has suggested four ways to fix the problem. They include non-destructive testing and crack-mapping of the girder to assess its strength, a design check of the girder by an IIT or an engineering institute of repute and finally ‘rehabilitation’ of the bridge using Carbon Fibre Reinforced Polymer (CFRP) composite technology.
It also suggested that the office of the Superintending Engineer of PWD (NH) located below the bridge be vacated if need arose.
A senior NHAI official said a linear crack had been detected on the two-lane bridge located on the western side. It is not a major one, and there is no reason to regulate or restrain traffic over it. The report has been forwarded to an independent agency. “It will report back to us, based on which a decision will be taken whether to entrust rectification of the crack to the firm which is engaged in collecting toll and maintaining the 16-km bypass corridor, by recasting it. Else, tenders will be floated to entrust the task to an expert agency,” he said.
The agency which inspected bridges has also reported smaller a shear crack on the Aluva flyover, he added.
Responding to the issue, PWD Secretary Kamala Vardhana Rao said the department would take up the matter with officials of MoRTH and Railways immediately and request them to rectify problems on the structures as soon as possible.