Abstract Manager

In the management of bridge assets, it has become accepted practice to use a bridge condition index to describe the overall condition of a bridge or culvert structure. In Canada, the index accepted by Canadian bridge owners is the Bridge Condition Index or BCI. The index can be used to report condition as a performance measure, set targets for condition, and to communicate condition to non-bridge engineers. But condition is only one indication of whether a structure can adequately meet demands of the users. In many countries a measure of overall sufficiency of the structure is reported. Typically, a sufficiency rating considers the structural adequacy of the bridge (eg. to carry legal loads safely), the functional adequacy of the bridge (eg width or height restrictions, safety of road alignment, barriers), and the essentiality for public use (consequences if structure is closed to traffic, traffic volume, detour length). In the USA, the Sufficiency Rating (SR) has traditionally been used to evaluate need for Federal funding.

A Sufficiency Index (SI) has been developed and is being tested by Canadian provincial and municipal bridge owners as a tool to evaluate the overall sufficiency / adequacy of bridges and culverts and communicate this to decision makers.  Calculated by the Department’s Bridge Management System (BMS), the SI considers appraisals of the functional adequacy of the structure for Load Carrying Capacity, Width and Height Restrictions, Adequacy of Roadway Alignment, Barriers, and other safety consideration. SI also considers Scour, Flood, Fatigue, and Seismic vulnerabilities, as well Condition and Criticality. Several of the vulnerabilities considered are particularly affected by climate change and extreme weather so this is proving to be a timely tool for agencies looking for guidance.

This presentation will present the engineering models that are inputs to the SI and share some application case studies from Canadian bridge owners applying the index in decision making.