AEROELASTIC EFFECTS ON A RECTANGULAR BOX-GIRDER BRIDGE

Rectangular box-girders are commonly used for prestressed concrete bri dges constructed by the balanced cantilever method. The aerodynamic ch aracteristics of such a girder, with width to depth ratio varying betw een 1.4 and 2.9, are investigated in a series of wind tunnel tests. Th e aeroelastic tests carried out with a low structural damping (damping ratio 0.2% of critical) revealed the presence of vortex shedding and galloping forces both in turbulent and smooth flow. Possible descripti on of these effects in terms of a linearized aerodynamic damping is di scussed. The RMS displacement estimate associated with such a damping parameter is compared to the monitored displacement data. Lift force i n the response calculation is taken into account according to Vickery' s stochastic model of across-wind loading, based on the data from pres sure measurement tests with a non-moving model. (C) 1998 Elsevier Scie nce Ltd. All rights reserved.