| Connecting the Canadian provinces of Prince Edward Island and New Brunswick, the Confederation Bridge is the world's longest pre-stressed concrete box girder bridge built over ice laden waters. With a total length of 12.9 km and a 100-year design life, the design of the Confederation Bridge was not covered by any code or standard that existed at that time. A structural monitoring program was initiated at the time of construction of the bridge and has been ongoing since its opening in 1997. This monitoring program is being carried out to measure the behaviour and performance of the bridge under various conditions and to obtain unique field performance information to assist engineers in the long-term management of the bridge.;The research reported in this thesis focused on the long-term trend of strain and deformation due to creep and shrinkage of the concrete and other phenomena which typically occur in prestressed concrete structures. Creep in concrete is described as a dimensional change in the material under the influence of sustained loading. In addition, whether subjected to load or not, concrete contracts on drying, and undergoes shrinkage. In general, time-dependent deformations of concrete, such as those caused by creep and shrinkage, may affect the serviceability, durability and stability of the structure.;Many studies have been completed to measure the effect of creep and shrinkage on concrete, but few of those studies have had data from a real structure that is exposed to all environmental elements, and not only those applied in a lab. In addition, laboratory studies are generally conducted on small specimen often less than 1 metre in length. The section of the Confederation Bridge which maybe considered the specimen for this study is 500 m long. Ten years of data was available for this project which is significant because records of actual long-term deformations of long span bridges are rare and the opportunity to calibrate design techniques with actual data is valuable in the design of other bridges.;Long-term deformations from the bridge are currently being measured by mechanical displacement transducers and vibrating wire strain gauges that are installed in the concrete at selected sections in the bridge. Data collected by this structural monitoring program was processed and analyzed to determine the trend of strain and deformation that has occurred over its first 10 years of service life principally due to creep and shrinkage of the concrete. These field values were then compared with predicted values and algorithms proposed to predict future trends for the long-term deformation of the bridge. The project was also used to develop and refine methodologies for long-term structural health monitoring. |
