Structural condition of several flyovers under the Kolkata Metropolitan Development Authority (KMDA) in different parts of the city are ‘very severe’ and they need ‘immediate attention’ to prevent incidents of collapse. The crowded and busy Sealdah flyover may collapse anytime, while many other Kolkata bridges may also meet similar fate. These assessments and recommendations have been made by two international giants ~ AECOM and STUPS ~ who are into designing and engineering of flyovers and bridges across the world.
Soon after the Majherhat Bridge collapse on 4 September, the two agencies engaged by the KMDA under the state urban develop ment (UD) department to make preliminary assessments of 15 out of 48 flyovers and bridges maintained by the authority have submitted their reports to the department last week.
The 15 flyovers and bridges include Sealdah, Ultadanga, Chingrighata, Bankim Setu, Kalighat Bridge, Bijan Setu, Arabinda Setu, Ambedkar Bridge, Durgapur Bridge, Chetla Bridge, Dhakuria Bridge, Sukanta Setu.
“There are vertical cracks at the bottom of the pier shaft which might lead to serious compression failure and sudden collapse,” states the AECOM report after an on-the-spot inspection at Sealdah flyover.
For Ultadanga flyover, “development of cracks (vertical and diagonal) in the concrete long girder might be due to inadequate strength of girder to carry the present traffic”, and Chingrighata flyover develops “torsional distress and buckling in steel girders is severe for steel composite bridge which may lead to progressive failure”, experts of the agency have stated in the report.
These three flyovers have been recommended for an immediate thorough health study and then necessary repair on a priority basis.
“In a few of the bridges, distress has been found which were caused from probable inability of the bridge to carry the traffic load for which it was designed.
“This is a serious phenomenon and needs to be addressed quickly for identifying retrofitting measures to rehabilitate the bridge. In a few other cases maintenance deficiency caused damaged to parts of the bridge which can also lead to serious failure,” the report said.
STUPS has recommended ‘immediate attention’ for four bridges~ Aurobindo Setu, Kalighat Bridge, Chingrighata Flyover and Bankim Setu ~ identifying their ‘condition ‘very severe’ and ‘severe’.
The agency has also recommended saying: “Proper study of all bridges is essential before concluding the structure safe or unsafe.”
Sources in the KMDA said the four-member expert committee comprising Mr Amitava Ghoshal, senior bridge expert, Mr Samiran Sen, an independent consultant, Mr Ashish Kumar Sen, chief engineer (KMDA) and Mr Bhaskar Sengupta, another chief engineer (KMDA), held a meeting to discuss the preliminary assessments and recommendations of the two international agencies at Nagarayan, the UD department headquarters at Salt Lake.
It is learnt that the government will publish expression of interests in newspapers to select agency or agencies for the repair work of these 15 flyovers.