Bangalore Metro: BMRCL Erects Portal Beam Structures To Save Road Space On Outer Ring Road

The Bangalore Metro Rail Corporation Limited (BMRCL) is changing the structural design of columns along an 18-km stretch of Outer Ring Road (ORR) to save carriageway space after construction.

BMRCL officials said that the change is being made at six spots. At the six spots where split flyovers stand, Metro pillars are being replaced by portal beam structures.

The Blue Line of the Metro, which will connect Central Silk Board Junction and Kempegowda International Airport, is scheduled to run between these split flyovers.

BMRCL officials mentioned that the previous designs would have resulted in the loss of space due to large pillars.

The change in Namma Metro's pillar design at split flyovers along Outer Ring Road is a positive development. However, it is important to note that the benefits of these changes will only be seen in the long term.

BMRCL is currently faced with a more immediate challenge: expediting work in the corridor and coordinating with other stakeholders such as business establishments and traffic police to minimise inconvenience for road users. While it is true that the stretch has been a nightmare for motorists even before the Metro work began, it is not fair to expect them to endure further difficulties.

BMRCL officials explained that portal beams are beams supported by columns at either end. Instead of constructing a large 2-metre-wide pillar, they will build two narrower columns to support the viaducts. Once construction is complete, traffic will be allowed to flow in one direction between the two pillars.

BMRCL is currently constructing portal beam structures at various locations including HSR Layout, Agara, Bellandur, Doddanekkundi, DRDO, and Deverabeesanahalli.

"To avoid wasting space between two flyovers, BMRCL is building the portal beam structure instead of constructing Metro pillars on the road median. Typically, one pillar requires 2 metre of space. By using the portal beam structure, we can make optimal use of the available space and allow traffic to move beneath the structure. This will provide road widths of 5.5-6 meters for traffic flow," explained BMRCL executive director Indra Bhushan Jha, reports the Times Of India.

According to the official, the columns will have heights ranging from 12m to 16m.

Constructing the elevated corridor on the stretch has been a big challenge for BMRCL due to the traffic density on ORR. The agency maintains that it is removing barricades to provide more space for traffic on the main carriageway wherever it completes viaduct work.