A SYSTEM AND A METHOD OF COUNTERACTING WIND INDUCED OSCILLATIONS IN A BRIDGE GIRDER

摘要

A system to counteract the oscillations induced by the wind in a bridge span (11) supported by long cables comprises a plurality of control faces (14, 15, 16, 17, 34, 35, 36) which are arranged to a substantially symmetrical manner with respect to the longitudinal axis of the bridge. The control faces are arranged to use energy of the wind in response to movement of the span of the bridge in order to reduce said movement. The control faces are divided into sections in the longitudinal direction of the bridge and a plurality of detectors (19, 26) is provided for measuring the movements of the bridge span. A local control unit (20, 25) associated with each control face section is arranged to control the control face section in response to information from one or more of said detectors. In a method according to the invention the control faces (14, 15, 16, 17, 34, 35, 36) are divided into sections in the longitudinal direction of the bridge and a plurality of detectors (19, 26) measure the movements of the span of the bridge, following which a local control unit (20, 25) associated with each control face section controls the control face section in question in response to information from one or more of said detectors.