Canadian highway bridge evaluation: a general overview of Clause 12 of CSA Standard CAN/CSA-S6-88

Because upgrading a bridge is usually far more costly than incorporating extra capacity at the design stage, a different approach is appropriate. Clause 12 of CAN/CSA-S6-88, published in 1990, was developed specifically for evaluation. The development of Clause 12 is reviewed, as is the philosophy of varying the load factors based on how well the loads are known, the consequences of failure, and other variables. An overview of Clause 12 is presented and reference is given to three companion papers describing the derivation of numerical values used in Clause 12 and their adaptation for the Standard. Key words: bridges, evaluation, assessment.