Exploring the important aspects of Delhi’s iconic cable-stayed bridge
The Signature Bridge, completed in 2018 across the Yamuna River in Delhi, is India’s first asymmetrical cable-stayed bridge. At 675 meters long with a 154-meter inclined pylon, it connects Wazirabad to East Delhi. Conceived to relieve traffic congestion and symbolize the city’s modern identity, the bridge doubles as a civic landmark. Its design and construction demanded cutting-edge engineering solutions to balance aesthetics, durability, and safety in a seismically active and geologically complex site.
The bridge’s most striking feature is its steel pylon leaning at 60 degrees. Standing taller than the Qutub Minar, it symbolizes a ship’s mast. This asymmetry was chosen to create visual drama while distributing forces efficiently to the foundations.
108 stay cables arranged in a fan pattern anchor the deck to the pylon. Each cable comprises multiple galvanized steel strands protected by polyethylene sheaths, transferring loads while allowing slender deck design.
The deck uses steel orthotropic panels topped with asphalt surfacing. Expansion joints and bearings ensure movement accommodation under thermal variation, traffic loads, and seismic action.
The deliberate asymmetry sets it apart from conventional bridges. This choice reduces mid-river piers, minimizing obstruction to water flow and navigation while achieving iconic aesthetics.
Building the Signature Bridge was a decade-long process, involving phased construction and advanced methods. Engineers confronted challenges of riverbed soil, heavy traffic diversion, and environmental safety.
Deep pile foundations reaching 60–80 meters were used to bypass weak alluvial soil and anchor into dense strata. Pneumatic caissons supported in-river sections, enabling dry placement of concrete below water level.
The pylon segments were fabricated from high-strength steel and assembled onsite through precision welding and bolting. Modular fabrication allowed transport and erection in difficult urban conditions.
Stay cables were installed sequentially to balance forces. Specialized tensioning equipment ensured uniform load distribution, while sensors monitored stress throughout construction.
The deck was constructed in segments, using cantilever erection balanced by stay cables. This minimized the need for scaffolding in the river, protecting its ecology and ensuring safety.
Constructing a mega-project in Delhi’s environment required addressing numerous technical and logistical hurdles:
High-performance reinforced concrete (up to M60 grade) was used in piers, piles, and deck slabs. Special admixtures ensured resistance to sulfate attack and minimized shrinkage.
The inclined pylon and girders used thousands of tonnes of structural steel, chosen for strength, ductility, and ease of fabrication into complex geometries.
Galvanized steel strands bundled in HDPE sheaths provided tensile capacity while resisting corrosion. Cable anchors were specially designed to bear massive loads safely.
Anti-corrosion paints and fire-resistant coatings extended steel durability, crucial for Delhi’s harsh summers and pollution.
The Signature Bridge was envisioned as a green and civic-friendly project. Engineers adopted LED lighting to reduce energy consumption while enhancing night-time visibility. Minimal mid-river piers preserved river hydraulics. Materials were selected for long life, lowering maintenance frequency. Its sleek silhouette, illuminated at night, transformed it into a cultural landmark and tourist attraction, reflecting Delhi’s evolving skyline.
It is India’s first asymmetrical cable-stayed bridge with an inclined pylon, combining structural efficiency with landmark aesthetics.
Initial work began in 2004, but delays and design revisions meant the bridge was finally opened to the public in 2018.
The stay cables carry the weight of the deck and transfer loads to the pylon, enabling longer spans without multiple mid-river supports.