Nagpur Metro's 257-metre engineering feat

Nagpur Metro's Phase-II expansion is advancing rapidly, with the construction of a 257-metre-long elevated bridge over railway tracks at Uppalwadi nearing completion. This technically challenging structure stands nearly 80 feet above the ground, built using a specialized engineering technique called the balanced cantilever method.

The bridge, part of the Reach-2A 6.92-km stretch connecting Phase-I to Lekha Nagar near Asha Hospital, will cross three major railway lines - Godhani-Kalamna, Chhindwara-Nagpur, and Khaparkheda - operated by the South East Central Railway.

The bridge's central span, spanning 110 metres directly above the railway tracks, will be flanked by two additional spans of 74 metres and 73 metres. Standing approximately 24 metres above the ground, the Metro rail level provides improved accessibility for commuters. While substructure work has been completed, the superstructure construction has commenced from the Kamptee end.

Utilizing the balanced cantilever technique, engineers construct the bridge section by section without needing scaffolding underneath. Concrete segments, ranging from 2.5 metres to 3.175 metres in length, are cast successively on either side of supporting pillars and connected using post-tensioning technology. A 150-tonne crane lifts steel rods and construction materials to the top of the pillars, while a 40-tonne specialized machine, called a form traveller, aids in casting and extending the concrete bridge sections towards the railway crossing.

This innovative method proves particularly useful at Uppalwadi, where ground-level obstructions are minimized during construction.