Quantification of subjective uncertainty included in empirical knowledge on bridge rating

The major part of a bridge rating which is the essence of a computer-aided bridge rating system has been formulated based on the subjective judgement of experts in related fields. A method for expressing knowledge acquired from questionnaires, which were filled out by experts, was developed by relating the knowledge with a membership function based on fuzzy set theory. The concept of various measures of fuzziness is used. Fuzziness inherent in empirical knowledge possessed by experts in bridge rating was extracted by the questionnaire surveys. The membership function was applied to the results of the surveys in an attempt to quantify empirical knowledge. The results are presented