Assystem designs Ranchi’s new landmark - A project easing city’s traffic congestion

For the residents of Ranchi, a daily commute that was once a source of frustration has now become a smooth and quick journey. This transformation is thanks to the new 2.34 km elevated corridor linking Mecon Roundabout (Doranda) to Siramtoli, via Rajendra Chowk. At the heart of this project are two unique cable-stayed bridges, designed by Assystem in India, which solved complex engineering puzzles to ease the city’s traffic.

Designing these bridges was no simple task. It required the engineering team to overcome two very different, but equally difficult, challenges.

• Cable-Stayed Bridge on Harmu River – Situated in a densely packed area, the location already had an existing old bridge. In addition, the presence of buildings left very little room to work with. Placing the massive foundations and pylons that would hold up a cable-stayed bridge seemed impossible. The challenge was to fit the design perfectly into this tight urban corridor, without disturbing the daily life of the area.
• The Railway Over Bridge (ROB) – The second bridge had to cross directly over a busy railway line. The critical rule was simple but tough: train movement could not be stopped. This meant all the major work, from lifting heavy sections, to installing cables, and placing the bridge deck, had to be done during night-time windows, in perfect coordination with Indian Railways.

Two different construction methodologies were adopted for the project. On one side, panels were supported by temporary trestles, while on the other side, the cantilever construction method was employed. This required precise alignment and accurate matching of the segments from both sides.

• Reduced Traffic: This project has dramatically cut travel times to the railway station and airport from 30 minutes to almost 10 minutes. This has also led to a decrease in air and noise pollution levels in the area.
• Boosting Connectivity: The improved link to the railway station and airport has resulted to better and efficient connectivity.

The cable-stayed bridges are not just structures of steel and concrete; they symbolise progress. For Assystem this project was a means to show how innovative engineering can solve urban problems while building a foundation for a sustainable present.