Design of Budapest New Danube Bridge, Hungary

New Danube Bridge in Budapest, designed by BuroHappold and UNStudio, along with the Hungarian specialist bridge designer firm CÉH, will be a stunning landmark cable-stayed bridge redefining the landscape of Budapest, while creating a long-awaited new connection between the South Buda districts and Csepel Island. The bridge accommodates a 2x2 road, a 2x1 combined tram and bus, two-way cycle lanes and footpaths on both sides. The five-span cable stayed bridge will comprise two inclined pylons with aesthetically pleasing shape. It will have a main span of 246.00 m crossing the Danube navigation route, at a skew angle of 73°. The main span will be supported by fore stays arranged symmetrically and perpendicular to the bridge deck centerline. Backstays, each comprising 4 concentrated stay cables will connect the top of the pylons to anchorage piers on the riverbanks. The design of the river piers was extensively studied at the very early design stages to provide both combined architectural and engineering solution. The design satisfies the navigation requirements, considers the hydraulic effects, and elegantly supports the bridge superstructure. Departing from the rectangular competition geometry, early stage river pier variations were aligned to be more streamlined and elegant. These variations were investigated using two dimensional numerical hydraulic simulations and a small-scale physical model. Downstream vortex shedding was observed at one of the pier types. In addition to conventional methods, state-of-the-art 3D CFD models were built to reveal the prevailing flow features and riverbed movements in the vicinity of the investigated river piers. The results of detailed studies performed on the different pier variants, refuted the significant extent of vortex shedding observed in the small-scale experiment. However, they made clear that fine tuning of the pier angle would produce a better solution considering complex stream conditions and different water levels.