Millennium Footbridge
The bridge is the first new bridge across the River Thames in central London in over a century. It is located between the Blackfriars Railway Bridge and the Southwark Bridge and links two important tourist attractions: St. Paul’s Cathedral and the new Tate Gallery of Modern Art.
The full bridge length is 320m with a mid-span of 144m between piers. From their highest point over the piers, high strength cables flank the deck, dipping in elevation and on plan towards the centre of the bridge. The piers are formed in slender reinforced concrete and are elliptical in shape.
For this project, sectional model tests on a 1:17 scale model were conducted. These tests enabled an evaluation to be made of the aerodynamic stability of the proposed bridge deck section with regard to vortex excitation and flutter. The wind tunnel tests, together with buffeting theory, also provided estimates on the wind-induced bridge accelerations and effective wind loads. Based on our recommendation, the cable strands were spread horizontally rather than being formed into a single bunch. This feature improved substantially the bridge’s resistance to flutter instability.
