Kochi: The final report submitted by an expert team from IIT Madras recommended only str-engthening of the Palarivattom bridge using concrete jacketing method and not reconstruction after demolishing the structure.
“We recommended strengthening of all piers and girders of the bridge using concrete jacketing method,” Prof P. Alagusundara-moorthy, who led the team that detected the structural deficiency and recommended rem-edial measures, told DC over phone.
Under the reinforced concrete jacketing met-hod, steel reinforceme-nt is made and concrete is added to increase the number of sections and achieve the required performance improvement.
“In the initial report, we had suggested repa-iring the cracks on pie-rs and girders using carbon fibre reinfo-rced polymers (DFRP) method, also known as carbon fibre wrapping. The change in the repair method was to further strengt-hen the bridge,” the pr-ofessor with the structural engineering division, department of civil engineering, said.
The state government opted for demolition and reconstruction of the bridge as suggested by Mr E. Sreedharan, principal advisor, DM-RC, who too inspected the bridge and found serious flaws in quality. PWD Minister G. Sudhakaran said the government accepted Mr Sreedharan’s suggestion as the IIT report did not provide any assurance regarding the longevity of the bridge. The government wanted it to last for over 80-100 years.
The IIT expert admitted there was no specific guarantee period mentioned in the report. “But micro concrete is stronger and durable than new concrete and will naturally last more,” he said.
Sources said Mr Sreedharan suggested total replacement of the RCC girders of the flyover with pre-stressed concrete girders (PSC) since the cost of strengthening the bridge as recommended by the IIT experts is over 50 per cent of the total replacement cost.
The 750-metre bridge, built at a cost of Rs 42 crore, was oened to traffic in October 2016. However, cracks started developing on girders and piers.
