Concepedia

Abstract

In a review of the lateral swaying motion experienced by the Millennium footbridge, London, it is considered that the excessive movement was not caused by the particular structural form but by a combination of high pedestrian density and lateral modes of vibration below 1.3 Hz. Such factors could cause similar movement on any other similar structure irrespective of form and perceived performance. The solution has been to add structural damping elements which increase the critical number of pedestrians necessary to cause such an excessive response beyond the number physically able to walk across the bridge. Tests have shown that the dynamic response of such footbridges remains stable until a critical number of people cross the bridge when the response increases rapidly. Similar responses on other comparable footbridges worldwide are reported.