CHENNAI: The state highways department has completed around 70% of the four-lane elevated corridor on Anna Salai and is planning to open it by the end of November.
The 3.2-km project, touted as the country’s first elevated corridor to be built directly above an operational metro tunnel, is being built using prefabricated steel components.
As the flyover runs above the underground metro line, the engineering complexity has pushed up the project cost to `621 crore, making it costlier than a conventional highway project.
The project is expected to reduce travel time between Teynampet and Saidapet on Anna Salai from about 30 minutes to just five minutes. It will also ease congestion at seven major intersections – Eldams Road, SIET College Road, Cenotaph Road, Nandanam, CIT Nagar, CIT Nagar 1st Main Road (towards T Nagar), and Jones Road.
According to sources, around 1.9 km of the flyover has been completed, while 46 of the total 69 piers have been erected. The Teynampet-Saidapet metro tunnel runs 14 to 15 metres beneath Anna Salai.
To avoid disturbing the tunnel, the highways department drilled only up to a depth of seven metres from the road surface to lay the flyover’s foundations. Of the total 3.2-km stretch, 2.4 km passes directly above the metro tunnel, including a 460-metre stretch over the Teynampet and Nandanam metro stations. The remaining 655 metres is along the non-metro stretch.
“Out of the total 69 piers, 46 have already been erected. Reinforced concrete deck slabs have been laid for about 2 km of the 3.2-km corridor. Of the 69 piers, 22 are on the non-metro stretch, while 41 portal frames covering the 460-metre section are being installed above the two metro stations. As of August 1, around 70% of the project has been completed,” a senior highways official said.
The project, originally scheduled for completion by September this year, was delayed mainly due to a shortage of labour.
“A large number of workers engaged in the fabrication of steel components had returned to their native places during the elections in April and did not come back immediately, slowing down production. They have now resumed work. Since construction activities at the site in Chennai are permitted only for six hours during the night, progress was initially slow. However, work has now gathered pace, and the project is expected to be completed by the end of November,” the official added.
Around 15,000 tonnes of prefabricated steel components, including piers, pier caps and girders, are being manufactured at factories in Gujarat and Telangana, and transported to Chennai for assembly. In addition, RCC deck segments, each measuring about 15 metres in length, are being transported to the site and placed over the girders.
S Varatharajan, a regular commuter from T Nagar, said, “Traffic diversions caused by both the flyover construction and Chennai Metro Rail Phase -II works have resulted in severe congestion on Anna Salai. The highways department should expedite the remaining works to minimise inconvenience to motorists.”