Bengaluru's Peenya flyover to shut for traffic for 60 hours next week

Bengaluru: Tumakuru Road will likely witness bumper-to-bumper traffic next week as the National Highways Authority of India (NHAI) plans to shut the Peenya flyover for all vehicular movement from 11 pm on January 16 to 11 am on January 19. 

The traffic block is necessary to conduct load tests on the 240 prestressed cables that have been added to strengthen the flyover. Based on the load test results, the flyover may be opened to all traffic in the coming weeks, said KB Jayakumar, Project Director (Bengaluru), NHAI. 

The 15-metre-wide, 4.2-km-long flyover starts at Peenya and ends at Nagasandra on Tumakuru Road, the crucial transit point for all northbound traffic. It was shut for traffic in December 2021 after prestressed cables in its three spans (distance between two pillars) gave way due to corrosion. 

In February 2022, authorities allowed light motor vehicles onto the flyover, but barred buses and trucks. In 2023, the NHAI launched a Rs 38.5-crore repair work that involved adding two cables into extra slots at every span and stressing them to strengthen the flyover. There are a total of 120 spans in the flyover. 

Jayakumar said the work had been completed. "We need to conduct load tests to assess the strength of the prestressed cables," he told DH. 

During the load test, eight trucks carrying 32 tonnes each will be run on the flyover for more than 48 hours. "We will not check the entire flyover. That will take a lot of time. We will check only two spans," he explained. The NHAI has identified spans connecting pillars 105-106 and 117-118 for the load test, he added. 

The test report will be submitted to a four-member expert committee headed by Prof Chandra Kishen JM, from the civil engineering department at the Indian Institute of Science (IISc). The committee's recommendations will be sent to the NHAI headquarters, which will decide on when to reopen the flyover for all vehicles, Jayakumar said. 

Prof Kishen had earlier told DH that the cables broke because of corrosion, which in turn happened due to the ingress of moisture and sunlight. The committee suggested giving four layers of protection to the cables (galvanising, greasing, epoxy coating and sheathing). 

As suggested by the committee, the NHAI will also replace all the existing 1,243 prestressed cables in the next six months. "We will remove and refix those cables so that corrosion doesn't affect them in the future. The work will not affect the traffic," Jayakumar said.