Ice Loads on the Confederation Bridge Piers

Abstract

The Confederation Bridge is a multi-span bridge which acts as a “fixed link” between New Brunswick and Prince Edward Island, Canada. The bridge opened in 1997 and cost approximately one billion dollars to construct. The Confederation Bridge is 12.9 kilometers long and sits approximately 40 meters above the water, with the exception of one section of the bridge that rises to approximately 60 meters to permit ship traffic to pass beneath it. The bridge is mostly comprised of high strength concrete and reinforcing steel, and rests on 44 piers that sit at a maximum depth of 35 meters of water. The bridge crosses the Atlantic Ocean over a stretch of water known as the Northumberland Strait. This particular body of water is well known for the amount of ice that forms on the channel from January to late April of each year, with ice pans measuring up to four kilometers in diameter and one meter thick. Therefore, the piers needed to be designed so that the forces created by the moving ice would not cause the piers to fail, and cause a catastrophic collapse of the bridge structure. However, such a design has never been done before; therefore no design data was available. The following paper will highlight a comparison of the method used to predict the annual ice loads on the bridge piers versus the actual loads generated from the ice as measured by equipment in the piers.