Engineering of the National Namaste Signature Bridge Pylon

Abstract

The National Namaste Signature Bridge in Delhi symbolically welcomes the world with the Indian welcoming pose, Namaste, its visual form having the emblem of a peacock’s feather on its main body. The very complex geometry of the 151 m high slanted steel pylon, meant to be twice the height of Qutub Minar supports a 575 m length deck having a cable-stayed span of 251 m, flanked by approach spans on either side of the main bridge. The steel composite deck integrated with the pylon is supported on spherical bearings having a capacity of 17,100 t, while eight backstays are anchored to specially designed pendulum bearings that can take an uplift of 6380 t, which in turn are anchored to a hybrid foundation of caissons and piles. The unprecedented nature of the design of the foundations, bearings and pylon called for ingenious and novel construction engineering and methodology to be evolved, whether for hybrid foundations, concrete technology, the erection of large capacity special type bearings, fabrication, trial assemblies, welding including very long and critical in situ welding of pylon base & finally segmental erection of three dimensionally varying pylon. In the paper while touching upon briefly the conception part of the other aspects like foundations, general arrangement etc., the detail deliberation on fabrication and segmental erection of three dimensionally varying pylon and steel girders has been made.