19.63-Metre Portal Beam Successfully Installed Near Butibori Flyover
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Nagpur: Maha Metro Nagpur has achieved a major engineering milestone under its Phase-2 expansion by successfully constructing and installing a 19.63-metre-long portal beam, the largest of its kind on the Butibori Metro corridor, near the Butibori Railway Overbridge (RoB). The complex operation was completed using an innovative precast prestressed construction technique, ensuring that traffic on the busy National Highway remained unaffected.
Portal beams are used to support metro viaducts at locations where constructing pillars in the road median or carriageway is not feasible. A total of 18 such portal beams are planned between Khapri and Butibori ESR Metro Station, where the highway width exceeds 15 metres on either side of the central divider.
The installation of the 19.63-metre-wide portal beam near the approach road to the Butibori flyover posed a significant engineering challenge. Using the conventional cast-in-situ method would have required prolonged road closures, potentially causing severe traffic congestion for two to three months.
To overcome this challenge, Maha Metro engineers adopted a precast prestressed technology. Instead of casting the entire beam as a single unit—which would have weighed approximately 252 metric tonnes and been extremely difficult to transport and lift—they divided it into two precast segments.
The first segment measured 9.5 metres and weighed 128 metric tonnes, while the second measured 5.53 metres and weighed 63 metric tonnes. The two segments were joined using a 1-metre stitch arrangement, supported by reinforced concrete at both ends, to create the complete 19.63-metre portal beam.
The critical installation was carried out during a four-hour window between 1:00 a.m. and 5:00 a.m. on July 28, using two 150-tonne cranes. The operation was completed successfully without disrupting traffic on the National Highway.
The successful installation of this portal beam is expected to accelerate construction on the Butibori Metro Line and help Maha Metro complete the corridor within the planned timeline. The achievement also highlights the use of advanced engineering solutions to execute large-scale infrastructure projects while minimizing inconvenience to the public.


