DYNAMIC MONITORING OF THE CONFEDERATION BRIDGE

SUMMARY The Confederation Bridge is one of the world's longest continuous prestressed concrete box girder bridge built over sea water. Because of its location and long span length, the bridge is subjected to significant dynamic loads due to wind, sea current, ice floe impact, earthquakes and heavy vehicles. This paper describes a long-term monitoring program on the dynamic behaviour and performance of the Confederation Bridge. The objectives and scope of the monitoring program, and the design and layout of the instrumentation, are presented. The network of monitoring instruments includes over 100 channels of accelerometers, dynamic tiltmeters, displacement transducers, strain gauges and wind anemometers, to obtain information about the vibrational behaviour of the various components of the bridge. Some ambient vibration data collected as part of the calibration and testing of the monitoring instruments are presented. The field measured data agree well with the results computed using three-dimensional finite element models of the bridge, thus confirming the proper installation and operation of the monitoring equipment. In the study of the dynamic properties of the bridge, the effects of the non-structural components, such as the barrier walls and pavement materials, and the interaction effect of the surrounding water are considered. The monitoring project will not only establish a large comprehensive database on the dynamic behaviour and performance of such a unique concrete structure, but will also provide information for effective maintenance of the facility