City’s first steel flyover to be ready in six months

City’s first steel flyover to be ready in six months
Deccan HErald

Bangalore is going to get yet another flyover this year, in the middle of overcrowded Majestic area, next to the railway station. But before you let out your frustrated sighs and tired cries, here is some consolation. You may not have to undergo the same trauma that the Airport Road and Ananda Rao flyover constructions have unleashed on hapless Bangaloreans. For the City is getting its first light-weight, easy to assemble, quick to build ‘steel’ flyover.

The 450-metre long flyover which will loop around the Shantala Circle to end in front of the railway station, will be made of steel and concrete. The tenders for the work are going to be announced by the Bangalore Development Authority (BDA) within the next few days and construction work will begin in March.

The flyover will be ready for use within six months, around September, says A T Samuel, Chief Consultant of Stup Consultants which will oversee the project.

Top priority

“This flyover is priority number one in our list,” BDA Commissioner M N Vidyashankar says.

Three more steel flyovers — two on the BDA’s hi-tech corridor and one on Trinity Circle — are also being proposed. Six similar flyovers have already been been constructed in Kolkata and New Delhi.

The steel girders and piers will be prefabricated at a yard and installed during night time. Each structural steel pier can be installed on the concrete piles and pilecap below the ground within two hours. A concrete deck will be provided for, to ensure smoother rides.

Maintenance

The steel flyovers are 50 per cent lighter than concrete ones and require low maintenance.

“It is a myth that only concrete flyovers are maintenance-proof. Steel is as competent as concrete in this regard. These steel flyovers will only have to be painted every few years to avoid rust,” explains Samuel.

The flyover will be constructed as per the Code on Composite Construction (Steel and Concrete) as per the Indian Road Congress standards.

Cost factor

One of the limiting factors of such flyovers is the cost which is 50 per cent higher than concrete ones, Samuel adds.

“However, we are looking at ways to cut costs. According to a comparative analysis we did recently, the cost difference may not be very wide,” he says.

The analysis suggests that while the flyovers at Hebbal and Central Silk Board cost Rs 13,000 and Rs 22,000 per square metre, the steel flyovers will cost Rs 22,000 per square metre. The cost estimation of the project is still under process. The flyover will get finance from BDA funds.

Challege, significance

The steel flyovers also pose an aesthetic challenge to the builders. As it requires welding and bolting, they could get crooked or asymmetrical. Therefore, the engineers should pay special attention to detailing work, adds Samuel.

However, Vidyashankar points out that utility is more important than beauty as far as flyovers are concerned.

“Even the best possible steel flyover designs may not be as aesthetically good as a concrete flyover. But these steel flyovers can last for up to 100 years and has a carrying capacity of 80 tonnes against 30-45 tonnes of a conventional flyover. Bangalore needs flyovers that are fast to build and reduces congestion, which is exactly what steel flyovers will offer,” Vidyashankar explains.