Commentary on Clause 12 Existing Bridge Evaluation of CAN3-S6-M78, Supplement No. 1-1980

Abstract

The publication of the new Clause 12 Existing Bridge Evaluation of CAN3-S6-M78 Design of Highway Bridges marks a radical departure from the conventional format of bridge design codes. For the first time bridges may be evaluated on the basis of reliability or probability of failure. The philosophy of Clause 12, a guide to its use, the derivation of the theory, and a discussion of the various coefficients used in the clause are given.

Evaluation of System‐Reliability Methods for Cable‐Stayed Bridge Design

“…These state-of-the-art analytical methods may nonetheless prove justified for the evaluation of existing structures for which reliability is questioned and which are found to be deficient using traditional deterministic analysis procedures. It could be a rational alternative to the use of reduced load factors proposed elsewhere (Foster et al 1981).…”

“…In the survey of individual truck weights, conducted by the Ontario Ministry of Transportation and Communication (MTC), and reported by Agarwal and Wolkowicz (1976), a superposition of three normal curves was found to best fit the curve of collected data (Foster et al 1981). The mean and standard deviation from the normal curve fitting the zone of heaviest trucks are 480 kN and 62.7 kN, respectively.…”

“…The probability distributions and statistical moments of common structural engineering random variables presented by Ellingwood (1983) and Ellingwood et al (1980) are deemed appropriate for this study; nonetheless, bridge live loads are not covered by those documents and require a separate assessment. The results of studies by Agarwal and Wolkowicz (1976), Buckland and Sexsmith (1981), Foster et al (1981), and Harman and Davenport (1979) are considered to define the live-load random parameters.…”