Yukon highway bridges: Reliability and retrofit for heavy ore-haul

A proposed ore-haul over eight Yukon bridges: was assessed using a probability-based procedure, sanctioned by the Canadian Bridge Code. The assessment procedure provides target reliability indices that depend on consequences, and it results in load factors that account for the degree of control of the load. With a few:exceptions, bridge reliability;was found to be acceptable with closely controlled ore truck weights that exceeded legal limits, even though some aspects of the bridges required strengthening for the legal loads, which had greater variability. The assessment provided a logical means to identify specific parts of the bridges that required strengthening, It also made it possible to determine the feasibility and method for permitting an extreme heavy equipment load to be carried over the bridges under close control.